• ETRI Journal
• /
• v.38 no.5
• /
• pp.941-951
• /
• 2016

In this paper, cognitive radio and simultaneous wireless information and power transfer (SWIPT) are effectively combined to design a spectrum-efficient and energy-efficient transmission paradigm. Specifically, a novel SWIPT-based primary-secondary cooperation model is proposed to increase the transmission rate of energy/spectrum constrained users. In the proposed model, a multi-antenna secondary user conducts simultaneous energy harvesting and information forwarding by means of power splitting (PS), and tries to maximize its own transmission rate under the premise of successfully assisting the data delivery of the primary user. After the problem formulation, joint power splitting and beamforming optimization algorithms for decode-and-forward and amplify-and-forward modes are presented, in which we obtain the optimal PS factor and beamforming vectors using a golden search method and dual methods. Simulation results show that the proposed SWIPTbased primary-secondary cooperation schemes can obtain a much higher level of performance than that of non-SWIPT cooperation and non-cooperation schemes.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.12
• /
• pp.1219-1228
• /
• 1991

In the actual case, a model of noise canceller using adaptive filter has both a channel transfer function from noise source to main signal input and to noise canceller input. The previous models of noise canceller have been considered to be only one side channel transfer function. Therefore, it is proposed that a new model has two channel transfer functions and derives an optimal tranfer function of adaptive noise canceller. The adaptive filter is using the joint process lattice filter that has fast adaptive speed. The signal noise radio has been improved by a model of ANC-ALE and it is confirmed with computer simulation. Beside, a dc bias is very effective for noise cancelling, especially to the particular signal.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.3
• /
• pp.303-312
• /
• 2007

Steel box girder bridges are being commonly designed for medium-span bridges of span length. Composite truss bridges with steel diagonals instead of concrete webs can be an excellent design alternative, because it can reduce the dead weight of superstructures. One of the key issues in the design of composite truss bridges is the joint structureconnecting the diagonal steel members with the upper and lower concrete slabs. Because the connection has to carry concentrated combined loads and the design provisions for the joint are not clear, it is necessary to investigate the load transfer mechanism and the design methods for each limit state. There are various connection details according to the types of diagonal members. In this paper, the joint structure with group stud connectors welded on a gusset plate is used. Push-out tests for the group stud connectors of were performed. The test results showed that the current design codes on the ultimate strength ofthe stud connection can be used when the required minimum spacing of stud connectors is satisfied. Flexure-shear tests were conducted to verify the applicability of the design provisions for combined load effects to the strength of joint structures. To increase the pullout strength of the connection, bent studs were proposed and utilized for the edge studs in the group arrangement of the joint. The results showed that the details of the joint structure were enhanced. Thereafter, design guidelines were proposed.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.31 no.4
• /
• pp.191-212
• /
• 2020

In this study, a study on the cooperative system of the Chungnam Library's joint preservation data center and a plan for the construction of the use service was proposed based on the analysis of the current status of the preservation library of the Chungcheongnam-do public library. In order to establish a cooperative plan for the joint preservation archive and to promote the provision of services, the current state of the collection of 62 public libraries in Chungnam-do and the status of the preservation archives that are operating separately were identified. As a result of the study, it was found that all matters related to the operation of the joint preservation archive should be made through agreements or consultations between the participants, and the operation of the joint preservation archive should also be made under a systematic cooperation system between the participants. To this end, it is necessary to establish a cooperative system for the Chungnam Library Joint Preservation Archives, and to form and operate the Joint Preservation Archives Steering Committee, a consultative body (cooperation network). In addition, all matters related to the operation of the Joint Preservation Archive, such as transfer criteria, must be regulated and implemented through consultation with the Joint Preservation Archive Steering Committee.

• Clinics in Shoulder and Elbow
• /
• v.12 no.2
• /
• pp.236-239
• /
• 2009

Purpose: We wanted to evalulate the clinical results of pectoris major tendon transfer for a neglected winged scapula that was caused by paralysis of the serratus anterior due to injury to the long thoracic nerve. Materials and Methods: A patient had neglected winged scapula that followed an arthroscopic operation for multi-directional instability of the shoulder joint, which was caused by traumatic dislocation. The patient was treated with pectoralis major tendon transfer using the modified Eden-Lange procedure. The range of a motion was improved from forward flexion $90^{\circ}$ and external rotation $70^{\circ}$ to $170^{\circ}$ and $150^{\circ}$ respectively. Results and Conclusion: There were no complications or recurrence and the patient's psychological satisfaction was also high. If the shoulder girdle muscles are intact, except for the serratus anterior, then pectoralis tendon transfer is a satisfactory method that can provide normal scapulo-thoracic motion.

• Physical Therapy Korea
• /
• v.27 no.2
• /
• pp.133-139
• /
• 2020

Background: The gastrocnemius (GCM) is one of the lower extremity muscles that tend to tighten easily. GCM tightness results in limited ankle dorsi-flexion (DF), especially when the knee joint is fully extended. Joint flexibility is determined by the morphological and physiological characteristics of joints, muscles, tendons, and ligaments. Impaired joint flexibility can be attributed to increased susceptibility to muscle injury. High-frequency diathermy is clinically used to reduce pain and muscle tightness and to improve limited range of motion. Objects: This study aimed to investigate the immediate effects of high-frequency therapy in subjects with GCM tightness. Methods: The study was designed as a one-group before-after trial. The subjects included 28 volunteers with GCM tightness (an active ankle DF angle of less than 12°) without any known neurological and musculoskeletal pathologies in the ankle and calf areas. WINBACK Transfer Electrode Capacitive and Resistive Therapy equipment was used to apply high-frequency therapy to the subjects' GCMs for 10-15 minutes. The pennation angle and the fascicle length of the GCM were measured using ultrasonography. The flexibility of the ankle joint, peak torque to the passive ankle DF (Biodex), and soft tissue stiffness (MyotonPRO) were also measured. Results: The pennation angle was significantly decreased following the treatment; however, no significant difference in the fascicle length was found (p < 0.05). The flexibility was significantly increased and both the passive peak torque to passive ankle DF and the soft tissue stiffness significantly decreased (p < 0.05). Conclusion: High-frequency therapy is immediately effective for improving the muscle's architectural properties and functional factors in subjects with GCM tightness. Further longitudinal clinical studies are required to investigate the long-term effects of high-frequency therapy on subjects with GCM tightness from various causes.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.2
• /
• pp.108-114
• /
• 2002

In this paper, nonlinear finite element analysis is performed to ensure structural safety and to suggest the design improvement of wing-to-fuselage joint of the KSR-III rocket. In the joint, wings are attached to fuselage by fitting wing attachment part into the groove on the fuselage frame, and load transfer between wing and fuselage frame is accomplished mainly throug the contact of two members as well as fastening bolts. The careful finite element modeling has been proposed for the purpose of analyzing problems with relatively complicated load path. The detailed bolt modeling is conducted and GAP elemets are used to simulate contact problem between joined members and bolts. The suggested design improvement is verified by structural testing and the analysis results are compared with test results.

• Archives of Reconstructive Microsurgery
• /
• v.16 no.2
• /
• pp.100-107
• /
• 2007

Treatment of giant cell tumor of distal radius can be treated in several ways according to the aggressiveness of the tumor. But the management of giant cell tumor involving juxta-articular portion has always been a difficult problem. In some giant cell tumors with bony destruction, a wide segmental resection may be needed for preventing to recur. But a main problem is preserving of bony continuity in bony defect as well as preservation of joint function. We have attempted to overcome these problems by using a microvascular technique to transfer the fibula with peroneal vascular pedicle or anterior tibial vessel as living bone graft. From April 1984 to July 2005, we performed the reconstruction of wide bone defect after segmental resection of giant cell tumor in 14 cases, using Vascularized Fibular Graft, which occur at the distal radius. VFG with peroneal vascular pedicle was in 8 cases and anterior tibial vessel was 6 cases. Recipient artery was radial artery in all cases. Method of connection was end to end anastomosis in 11 cases, and end to side in 3 cases. An average follow-up was 6 years 6 months, average bone defect after wide segmental resection of lesion was 6.8 cm. All cases revealed good bony union in average 6.5 months, and we got the wide range of motion of wrist joint without recurrence and serious complications. Grafted bone was all alive. In functional analysis, there was good in 7 cases, fair in 4 cases and bad in 1 case. Pain was decreased in all cases but there was nearly normal joint in only 4 cases. Vascularized fibular graft around wrist joint provided good functional restoration without local recurrence.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.19 no.4
• /
• pp.1-9
• /
• 2015

This study is on the shear strength of the internal joints of RCS composite structure consisting of reinforced concrete column and steel beam. As a newly structure system, the composite system has been developed to fully utilize the advantages of reinforced concrete column and steel beam, which also include economic and practical joint detail. Nevertheless stress transfer mechanism and structural behavior of the joints had not been still clearly revealed and shown much difference from the proposed equation. In this study, by observing the crossing of reinforced concrete column through steel beam to the RCS structure beam type, thirty seven shear failure specimens were selected and applied to the 5 major equations which is used to calculate the shear strength of RCS joint. Through the regression analysis, modified equation which is more reliable and approximate results for shear strength of RCS joints was proposed.

• Imaging Science in Dentistry
• /
• v.52 no.4
• /
• pp.393-398
• /
• 2022

Purpose: This study proposed a generative adversarial network (GAN) model for T2-weighted image (WI) synthesis from proton density (PD)-WI in a temporomandibular joint(TMJ) magnetic resonance imaging (MRI) protocol. Materials and Methods: From January to November 2019, MRI scans for TMJ were reviewed and 308 imaging sets were collected. For training, 277 pairs of PD- and T2-WI sagittal TMJ images were used. Transfer learning of the pix2pix GAN model was utilized to generate T2-WI from PD-WI. Model performance was evaluated with the structural similarity index map (SSIM) and peak signal-to-noise ratio (PSNR) indices for 31 predicted T2-WI (pT2). The disc position was clinically diagnosed as anterior disc displacement with or without reduction, and joint effusion as present or absent. The true T2-WI-based diagnosis was regarded as the gold standard, to which pT2-based diagnoses were compared using Cohen's ĸ coefficient. Results: The mean SSIM and PSNR values were 0.4781(±0.0522) and 21.30(±1.51) dB, respectively. The pT2 protocol showed almost perfect agreement(ĸ=0.81) with the gold standard for disc position. The number of discordant cases was higher for normal disc position (17%) than for anterior displacement with reduction (2%) or without reduction (10%). The effusion diagnosis also showed almost perfect agreement(ĸ=0.88), with higher concordance for the presence (85%) than for the absence (77%) of effusion. Conclusion: The application of pT2 images for a TMJ MRI protocol useful for diagnosis, although the image quality of pT2 was not fully satisfactory. Further research is expected to enhance pT2 quality.