• Title/Summary/Keyword: Compression-Only

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Seismic behavior of full-scale square concrete filled steel tubular columns under high and varied axial compressions

  • Phan, Hao D.;Lin, Ker-Chun
    • Earthquakes and Structures
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    • v.18 no.6
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    • pp.677-689
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    • 2020
  • A building structural system of moment resisting frame (MRF) with concrete filled steel tubular (CFST) columns and wide flange H beams, is one of the most conveniently constructed structural systems. However, there were few studies on evaluating seismic performance of full-scale CFST columns under high axial compression. In addition, some existing famous design codes propose various limits of width-to-thickness ratio (B/t) for steel tubes of the ductile CFST composite members. This study was intended to investigate the seismic behavior of CFST columns under high axial load compression. Four full-scale square CFST column specimens with a B/t of 42 were carried out that were subjected to horizontal cyclic-reversal loads combined with constantly light, medium and high axial loads and with a linearly varied axial load, respectively. Test results revealed that shear strength and deformation capacity of the columns significantly decreased when the axial compression exceeded 0.35 times the nominal compression strength of a CFST column, P0. It was obvious that the higher the axial compression, the lower both the shear strength and deformation capacities were, and the earlier and faster the shear strength degradation occurred. It was found as well that higher axial compressions resulted in larger initial lateral stiffness and faster degradation of post-yield lateral stiffness. Meanwhile, the lower axial compressions led to better energy dissipation capacities with larger cumulative energy. Moreover, the study implied that under axial compressions greater than 0.35P0, the CFST column specimens with B/t limits recommended by AISC 360 (2016), ACI 318 (2014), AIJ (2008) and EC4 (2004) codes do not provide ultimate interstory drift ratio of more than 3% radian, and only the limit in ACI 318 (2014) code satisfies this requirement when axial compression does not exceed 0.35P0.

Appropriateness of Selecting the Chest Compression Site by Lay-Persons: Compared to the center of the lower half of the breastbone and above the two fingers on solar plexus

  • Choi, Sung-Soo;Han, Seung-Tae;Yun, Seong-Woo
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.12
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    • pp.211-217
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    • 2020
  • This study is to find out the effectiveness by adult CPR method of a single rescuer. For patients with acute cardiac arrest, CPR is the only first aid, and chest compression is the most important of these techniques. The subjects of this study were freshman, 120 subjects who did not learn CPR, and for data analysis, the SPSS 22.0 Version was used. The accuracy of chest compression site selection was significantly higher in the upper part of the two fingers in the pit of the stomach(p<.001), and the ease was also high(p<.001). In the case of the general public, they select the chest compression area easily and quickly, it turns out that it is easier to designate the landmark toward the pit of the stomach. In the future, through various job groups, research to select the chest compression site is needed, and additional studies should be conducted to confirm the maintenance and accuracy during chest compression.

In-memory Compression Scheme Based on Incremental Frequent Patterns for Graph Streams (그래프 스트림 처리를 위한 점진적 빈발 패턴 기반 인-메모리 압축 기법)

  • Lee, Hyeon-Byeong;Shin, Bo-Kyoung;Bok, Kyoung-Soo;Yoo, Jae-Soo
    • The Journal of the Korea Contents Association
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    • v.22 no.1
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    • pp.35-46
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    • 2022
  • Recently, with the development of network technologies, as IoT and social network service applications have been actively used, a lot of graph stream data is being generated. In this paper, we propose a graph compression scheme that considers the stream graph environment by applying graph mining to the existing compression technique, which has been focused on compression rate and runtime. In this paper, we proposed Incremental frequent pattern based compression technique for graph streams. Since the proposed scheme keeps only the latest reference patterns, it increases the storage utilization and improves the query processing time. In order to show the superiority of the proposed scheme, various performance evaluations are performed in terms of compression rate and processing time compared to the existing method. The proposed scheme is faster than existing similar scheme when the number of duplicated data is large.

The Effect of Trunk Muscle Exercise of Paramedic Student on Cardiopulmonary Resuscitation (응급구조학과 학생들의 체간근육 훈련이 심폐소생술에 미치는 영향)

  • Yang, Hyun-Mo;Kim, Gyoung-Yong
    • Journal of the Korea Convergence Society
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    • v.12 no.5
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    • pp.71-77
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    • 2021
  • The present study aimed to find out how the trunk muscles, which are mainly used in Cardio-Pulmonary Resuscitation, affect chest compression through plank exercise. Study subjects participated in a 12-week program, and subjects performed only chest compressions for 8 minutes. Regarding their change in a muscle mass by plank exercise, there was a statistically significant difference in the change from 4th to 8th week after the program(p<.01). The muscle activity change had a statistically significant difference from 3rd to 10th week(p<.01). The chest compression depth had a statistically significant difference from 4th to 8th week(p<.01). In addition, insufficient chest relaxation height after compression had a statistically significant difference from 4th to 10th week(p<.01). The chest compression maintenance time had a statistically significant difference from 2nd to 12th week(p<.01). The participants' muscle mass and muscle activity increased more after their participation in plank exercise program than before. All chest compression factors except for chest compression rate brought about positive results.

Effect of Wearing a Compression Stocking on Electromyogram of the Legs (동일인에서 한쪽 다리에만 압박스타킹을 착용했을 때 유발되는 다리 근육의 근전도 변화에 대한 정량적 분석)

  • Lee, Ji-Youn;Yuk, So-Hee;Yoo, Hyo-Gyung;Hong, Nam-Ju;Jeon, In-Cheol;Jung, Dongju
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.2
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    • pp.185-190
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    • 2019
  • Compression stockings are widely used for prevention of varicose vein. Depending on manufacture, there are diverse types of compression stockings available. Most common type of compression stocking might be the one cover calf of a lower leg which has 20~30 mmHg pressure. Despite being widely used, possible side effects that may occur by wearing compression stockings have not been studied much. We analyzed for a long wearing effect of compression stocking. Participants wore the compression stocking over one leg for 7 days. During the period, all the participants did their ordinary works wearing the compression stocking. Electrocardiogram (ECG), ankle-brachial index (ABI), blood pressure (BP), and electromyogram (EMG) were measured at 0 day, 3rd day and 7th day. There was no effect of wearing compression stockings from ECG, ABI or BP. Only EMG that was measured on the covered muscle increased proportionally to the wearing time. Interestingly, EMG from the opposite leg that had never been covered by compression stocking decreased in proportion to the wearing date. These results suggest wearing a compression stocking for varicose vein may cause unintentional increase or decrease of EMG from the wearing or non-wearing legs, respectively.

Infranuchal Infrafloccular Approach to the More Vulnerable Segments of the Facial Nerve in Microvascular Decompressions for the Hemifacial Spasm

  • Park, Heung-Sik;Chang, Dong-Kyu;Han, Young-Min
    • Journal of Korean Neurosurgical Society
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    • v.46 no.4
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    • pp.340-345
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    • 2009
  • Objective : We investigated the locations of compressing vessels in hemifacial spasm. To approach compression sites, we described and evaluated the efficacy of the infranuchal infrafloccular (INIF) approach. Methods : A retrospective review of 31 consecutive patients who underwent microvascular decompression (MVD) through INIF with a minimum follow-up of 1 year was performed. Along the intracranial facial nerve, we classified the compression sites into the transitional zone (TRZ), the central nervous system (CNS) segment and the peripheral nervous system (PNS) segment. The INIF approach was used to inspect the CNS segment and the TRZ. Subdural patch graft technique was used in order to achieve watertight dural closure. The cranioplasty was performed using polymethylmethacrylate. The outcome and procedure-related morbidities were evaluated. Results : Twenty-nine patients (93%) showed complete disappearance of spasm. In two patients, the spasm was resolved gradually in 2 and 4 weeks, respectively. Late recurrence was noted in one patient (3%). The TRZ has been identified as the only compression site in 19 cases (61.3%), both the TRZ and CNS segment in 11 (35.5%) and the CNS segment only in 1 (3.2%). There was no patient having a compressing vessel in the PNS segment. Infection as a result of cerebrospinal fluid leak occurred in one patient (3%). Delayed transient facial weakness occurred in one patient. Conclusion : The TRZ and the CNS segment were more vulnerable area to the compression of vessels. We suggest that surgical avenue with the INIF approach provides early identification of this area.

A High Image Compression for Computer Storage and Communication

  • Jang, Jong-Whan
    • The Journal of Natural Sciences
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    • v.4
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    • pp.191-220
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    • 1991
  • A new texture segmentation-based image coding technique which performs segmentation based on roughness of textural regions and properties of the human visual system (HVS) is presented. This method solves the problems of a segmentation-based image coding technique with constant segments by proposing a methodology for segmenting an image texturally homogeneous regions with respect to the degree of roughness as perceived by the HVS. The fractal dimension is used to measure the roughness of the textural regions. The segmentation is accomplished by thresholding the fractal dimension so that textural regions are classified into three texture classes; perceived constant intensity, smooth texture, and rough texture. An image coding system with high compression and good image quality is achieved by developing an efficient coding technique for each segment boundary and each texture class. For the boundaries, a binary image representing all the boundaries is created. For regions belonging to perceived constant intensity, only the mean intensity values need to be transmitted. The smooth and rough texture regions are modeled first using polynomial functions, so only the coefficients characterizing the polynomial functions need to be transmitted. The bounda-ries, the means and the polynomial functions are then each encoded using an errorless coding scheme. Good quality reconstructed images are obtained with about 0.08 to 0.3 bit per pixel for three different types of imagery ; a head and shoulder image with little texture variation, a complex image with many edges, and a natural outdoor image with highly textured areas.

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"In the Beginning was the Deed": Sigmund Freud's Auditory Imagination

  • KIM, TaeChul
    • English & American cultural studies
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    • v.9 no.1
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    • pp.113-139
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    • 2009
  • Such is an elective affinity between literary studies and psychoanalysis that the latter sometime serves as a form of literary pedagogy. The affinity mainly consists in their shared concern for language. The signification of language in psychoanalysis is much similar to that of literature. Many of psychoanalytic terms and theoretical tenets bear witness to its dependence clinically on speech phenomena and theoretically on language in general. It is most true of Sigmund Freud, for whom the unconscious is in effect the linguistic unconscious. The Freudian unconscious, compressing and displacing through images and ideas, works as a text for psychoanalysis, which approach has not only paved one of the ways to poststructuralist anti-essentialism but with which literary studies also feel uncanny familiarity. Freudian psychoanalysis, starting empirically from clinical observations, discovers that words exist independent of meanings in the form of things in the unconscious system. Out of the various sensory elements of a word-thing, in psychoanalytic terms, the auditory is central. Now with the auditory imagination cultivated in the clinic, Freud figures out compression and displacement as the chief unconscious works, of which my main argument is that they are based phonetically on heteronym and homonym associations respectively. Compression and displacement work to be masks, which excites Freud's sense of challenge: his is a kind of poststructuralist approach, in the sense that the closed interrelatedness of words without external referents determines the signification in a given situation. But the works of compression and displacement, viewed in auditory terms rather than mapped on to metaphor and metonymy, can provide a new insight for a literary reading of Freud. Pursuing Freud's auditory imagination is not only an attempt to read his writing as literary text rather than for theoretical discussion, but also an experiment with the possibility of literary reading of a theoretical text in the age of after-theory.

Analysis of the Dynamic Behavior and Characteristics of the CNG Compressor Considering Bearing Characteristics (베어링 특성을 고려한 CNG 압축기의 동적 거동 및 동특성 해석)

  • Kim, Tae-Jong
    • Tribology and Lubricants
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    • v.22 no.6
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    • pp.342-349
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    • 2006
  • In this study, a dynamic behavior of rotor-bearing system used in CNG compressor has been investigated using the combined methodologies of finite elements and transfer matrices. The finite element is formulated including the field element for a shaft section and the point element for roller bearings. The Houbolt method is used to consider the time march for the integration of the system equations. The transient whirl response of rotating shaft supported on roller bearings is obtained, considering compression forces and unbalance forces at eccentric crank-pin part. And, the steady state displacements of the rotor are compared with a variation in stiffness coefficient of roller bearings. Results show that the loci of crankshaft considering unbalance forces and external compression forces are more severe in whirl motion than with only unbalance forces.

Sub-pixel Motion Estimation Algorithm with Low Computation Complexity for H.264 Video Compression (H.264 동영상 압축을 위한 낮은 복잡도를 갖는 부 화소 단위에서의 움직임 추정)

  • Lee, Yun-Hwa;Shin, Hyun-Chul
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.639-642
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    • 2005
  • Motion Estimation(ME) is an important part of video compression, because it requires a large amount of computation. Half-pixel and quarter-pixel motion estimation allows high video compression rates but it also has high computation complexity. In this paper we suggest a new and efficient motion estimation algorithm for half-pixel and quarter-pixel motion estimation using SAD values. In the method, an integer-pixel motion vector is found and then only three neighboring points of the integer-pixel motion vector is evaluated to find the half-pixel motion vector. The quarter-pixel motion vector is also found by using a similar method. Experimental results of our method shows 20% reduction in computation time, when compared with those of a conventional method, while producing same quality motion vectors.

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