• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.1
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• pp.58-66
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• 2012

Even after establishment of H.264/AVC standard, the video coding experts group (VCEG) of ITU-T has researched on development of promising coding techniques to increase coding efficiency based on the key technology area (KTA) software. Recently, the joint collaboration team video coding (JCT-VC) which was composed of the VCEG and the motion picture experts group (MPEG) of ISO/IEC is developing a next-generation video standard namely HEVC intended to gain twice efficiency than H.264/AVC. An adaptive interpolation technique, one of various next-generation techniques, reported higher coding efficiency. However, it has high computational complexity and does not deal with various error characteristics for videos. In this paper, we investigate characteristics of interpolation filters and propose an effective fixed interpolation filter bank including diverse properties of error. Experimental results is shown that the proposed method achieved bitrate reduction by 0.7% and 1.3% compared to fixed directional interpolation filter (FDIF) of the KTA and the directional interpolation filter (DIF) of the HEVC test model, respectively.

• Composites Research
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• v.33 no.3
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• pp.115-124
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• 2020

Laminate composites, especially Carbon fiber-reinforced composites are wide used in various industry such as aerospace and automotive industry due to their high specific strength and specific stiffness. However, the laminate composites has a big disadvantage that delamination occurs because the arrangement of the fibers is all arranged in the in-plane direction, which limits the field of application of the laminate composites. In this study, we first developed a laminate composites T-beam in which π-beam and flat plate were combined and optimized the design parameters through structural analysis and mechanical tests. Afterwards, 3D weave preform T-beam was developed by applying the same design parameters of laminate composites T-beams, and improved mechanical strength was achieved compared to laminated structures. These findings are expected to be applicable to existing laminated composite structures that require increased strength.

• Physical Therapy Korea
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• v.21 no.4
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• pp.1-8
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• 2014

Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that delivers low-intensity direct current to cortical areas, thereby facilitating or inhibiting spontaneous neuronal activity. This study was designed to investigate changes in various sensory functions after tDCS. We conducted a single-center, single-blinded, randomized trial to determine the effect of a single session of tDCS with the current perception threshold (CPT) in 50 healthy volunteers. Nerve conduction studies were performed in relation to the median sensory and motor nerves on the dominant hand to discriminate peripheral nerve lesions. The subjects received anodal tDCS with 1 mA for 15 minutes under two different conditions, with 25 subjects in each groups: the conditions were as follows tDCS on the primary motor cortex (M1) and sham tDCS on M1. We recorded the parameters of the CPT a with Neurometer$^{(R)}$ at frequencies of 2000, 250, and 5 Hz in the dominant index finger to assess the tactile sense, fast pain and slow pain, respectively. In the test to measure CPT values of the M1 in the tDCS group, the values of the distal part of the distal interphalangeal joint of the second finger statistically increased in all of 2000 Hz (p=.000), 250 Hz (p=.002), and 5 Hz (p=.008). However, the values of the sham tDCS group decreased in all of 2000 Hz (p=.285), 250 Hz (p=.552), and 5 Hz (p=.062), and were not statistically significant. These results show that M1 anodal tDCS can modulate sensory perception and pain thresholds in healthy adult volunteers. The study suggests that tDCS may be a useful strategy for treating central neurogenic pain in rehabilitation medicine.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.2
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• pp.89-97
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• 1997

Twenty hundred and five out of 266 patients who were registered in Korea Cancer Center Hospital from Mar. 1985 to Jan. 1994, were analyzed in the aspect of survival and local recurrence. Fifty one patients were excluded due to inadequate data and follow up. Prognostic factors for survival were evaluated statistically. One hundred and four cases were male, 101 female. Average age was 39.7(range 1 to 77) year with a peak incidence around 4th decade. The most frequent diagnosis was malignant fibrous histiocytoma(MFH)(24.1%). Liposarcoma, synovial sarcoma, rhabdomyosarcoma, malignant peripheral nerve sheath tumor and fibrosarcoma were relatively common diagnostic entities, in decreasing order. In location, extremity was 179(87.3%) and trunk 26(12.7%). Average follow up period was 7.5 years(6 months to 10 years). Actuarial 5 years and 10 years survival rate were 64.0% and 40.8% respectively. In univariate analysis with log-lank test, significant differences in survival rate were noted in histopathological diagnosis, size(10 cm), stage and metastasis. Age, sex, tumor location, tumor depth and local recurrence didn't affect the survival rate. Adjuvant chemotherapy and/or radiotherapy did not affect overall survival rate, but lowered the local recurrence rate when compared with surgery only. Surgical margin did not affect the survival rate, but local recurrence rate was different according to each margin; 5.7% in more than wide; 39.5% in marginal; and 60.0% in intralesional excision. In multivariate analysis for results of univariate analysis with Cox's propotional model, metastasis was a meaningful factor for survival of soft tissue sarcoma.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.1001-1009
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• 2005

The usefulness of walls in the structural planning of multistory buildings has long been recognized. When walls are situated in advantageous positions in a buildings, they can be very efficient in resisting lateral load. Specially coupled shear wall system is the primary lateral load resisting system of buildings. It is customary to refer to such walls as being 'coupled' by coupling beams. The coupling beams must exhibit excellent strength, stiffness ductility and energy dissipation capacity. To achieve these demands for steel coupling beam, steel coupling beam with Face Bearing Plate(FBP) embedded in the reinforced concrete walls is proposed. A comprehensive experimental test involving 2 steel coupling beam with and without FBP has been performed. Through experimental study, the evaluation of the advantage of that was establish and proposed the failure mode.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.3
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• pp.410-416
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• 2007

There are many demands for interoperability between weapon systems as the operational needs for joint and coalition based on network in modern and future warfare have been increasingly needed. In DoD, LISI has been applied throughout information system life cycle from the planning phase to the development phase to assess the level of interoperability. We also developed SITES which is a tool to assess the level of interoperability in information systems. But we should extend the assessment model from the previous information systems to the weapon systems to assess the level of interoperability including weapon systems as well as information systems. In this paper, we proposed the assessment model of interoperability, implemented the E-SITE based on the proposed model, applied 12 weapon systems and analyzed the experimental result.

• Physical Therapy Korea
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• v.8 no.2
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• pp.17-27
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• 2001

The purpose of this study was to investigate the effect of donning of a hard insole in patients with hallux valgus. Fourteen subjects were selected from patient with foot pain at Lee Chang-Heon Foot Clinic from August 4, 2000 to September 15, 2000. The hallux valgus angle and the first-second intermetatarsal angle were radiographically measured before and after donning the hard insole. Based on these two kinds of angles, a mild hallux valgus deformity group was characterized by the hallux valgus angle of less than 20 degrees, and a moderate hallux valgus deformity group was characterized by the hallux valgus angle of 20 to 40 degrees. After three weeks with the hard insole donned, the foot angles of the patients with hallux valgus were measured again. The data were analyzed by Wilcoxon signed ranks test, and the following results were obtained: 1) After the trial, both mild hallux valgus deformity group and moderate hallux valgus deformity group demonstrated that the hallux valgus angles were significantly decreased. 2) After the trial, mild hallux valgus deformity group demonstrated that the first-second intermetatarsal angle was significantly decreased. 3) After the trial, moderate hallux valgus deformity group demonstrated that the first-second intermetatarsal angle was not significantly decreased. The above findings revealed that according to donning hard insole, the hallux valgus angles of mild and moderate hallux valgus deformity groups and the first-second intermetatarsal angle of mild hallux valgus deformity group were significantly decreased. The results of this study have some limitation for generalization due to the limited number of subjects. Further studies are needed to evaluate the effect of hard insole on hallux valgus with more precise laboratory equipments and measurements in patients with hallux valgus.

• Genomics & Informatics
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• v.7 no.1
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• pp.20-25
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• 2009

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that is characterized by inflammation of the synovial tissue and deterioration of the joint and bone. A recent study reported a potential gene-environment interaction between HLA-DR and smoking. The present study investigated whether a specific gene was related to the association between smoking and the severity of RA (rheumatoid factor levels > 20 IU/ml). We used the resources of the NARAC family collection of GAW 15 databases, and 1139 subjects with RF>20 IU/ml were included in the current analysis. The linkage panel contained 5858 SNP markers, and 5744 SNPs passed quality control criteria. Linear regression analyses, using PLINK software and generalized estimating equation regression models, were used to test for associations between the SNPs and the severity of RA according to smoking groups. Two major findings were established. First, the severity of RA in smokers was associated with rs703618 (p=$6{\times}10^{-5}$), which lies in the intronic region of the stabilin 2 (STAB2) gene on chromosome 12. Second, there were significant differences in the levels of RF between 'ever smokers' and 'never smokers' according to the rs703618 genotype (G/G, A/G, A/A). We investigated whether a specific gene acts as a mediator between smoking and the severity of RA and found that the STAB2 gene could affect this relationship. Our finding indicates that smoking may mediate RA severity by affecting the expression level of a specific gene.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.6
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• pp.63-68
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• 2007

The purpose of this study was to develop a new connection method between steel beams and PC columns known as SL connectors. Composite moment frames consisting of PC columns (or composite columns) and steel beams make the best use of advantages of both concrete and steel materials. However, the connection between two members of different materials can be complex and/or increase the fabrication costs significantly. The concept of SL connectors is based on using wedges and the emphasis is on a self-locking (SL) feature. SL connectors are easy to install and provide better seismic performance compared to conventional connections. To evaluate the seismic performance of the steel beam-to-PC column joints with SL connectors, cyclic load tests were conducted. Test result showed that steel beam-to-concrete column joint with SL connectors was able to provide sufficient performance for use in seismic resistant moment frames.

• Steel and Composite Structures
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• v.23 no.6
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• pp.727-736
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• 2017

The application of carbon fiber reinforced polymer (CFRP) in steel structures primarily includes two categories, i.e., the bond-critical application and the contact-critical application. Debonding failure and buckling failure are the main failure modes for these two applications. Conventional electrometric techniques may not provide precise results because of the limitations associated with single-point contact measurements. A nondestructive full-field measurement technique is a valuable alternative to conventional methods. In this study, the digital image correlation (DIC) technique was adopted to investigate the bond behavior and buckling behavior of CFRP-steel composite members. The CFRP-to-steel bonded joint and the CFRP-strengthened square hollow section (SHS) steel column were tested to verify the suitability of the DIC technique. The stereo-DIC technique was utilized to measure continuous deformation. The bond-slip relationship of the CFRP-to-steel interface was derived using the DIC data. Additionally, a multi-camera DIC system consisting of four stereo-DIC subsystems was proposed and applied to the compressive test of CFRP-strengthened SHS steel column. The precise buckling location and CFRP delamination of the CFRP-strengthened SHS steel column were identified. The experimental results confirm that the stereo-DIC technique can provide effective measurements for investigating the behaviors of CFRP-steel composite members.