• The korean journal of orthodontics
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• v.46 no.2
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• pp.73-80
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• 2016

Objective: The purpose of this study was to investigate the static (SFF) and kinetic frictional forces (KFF) in sliding mechanics of hybrid bracket systems that involve placing a conventional bracket (CB) or active self-ligating bracket (ASLB) on the maxillary anterior teeth (MXAT) and a passive SLB (PSLB) on the maxillary posterior teeth (MXPT). Methods: The samples consisted of two thoroughbred types (group 1, anterior-CB + posterior-CB; group 2, anterior-ASLB + posterior-ASLB) and four hybrid types (group 3, anterior-CB + posterior-PSLB-type 1; group 4, anterior-CB + posterior-PSLB-type 2; group 5, anterior-ASLB + posterior-PSLB-type 1; group 6, anterior-ASLB + posterior-PSLB-type 2) (n = 13 per group). After maxillary dentition alignment and maxillary first premolars removal in the stereolithographically-made typodont system, a $0.019{\times}0.025$-inch stainless steel wire was drawn through the right quadrant of the maxillary arch at 0.5 mm/min for 5 min. The SFF and KFF were measured with a mechanical testing machine and statistical analyses were performed. Results: Four different categories of SFF and KFF were observed among all groups (all p < 0.001). Group 1 demonstrated the highest SFF and KFF; groups 4 and 3 were second and third highest, respectively. The fourth category included groups 2, 5, and 6. Placing PSLBs on the MXPT resulted in significant SFF and KFF reductions in cases with CBs on the MXAT, but not in cases with ASLBs on the MXAT. Conclusions: These data might aid in the development of a hybrid bracket system that enables low-friction sliding of an archwire through the MXPT.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.350-358
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• 1998

Antiphospholipid antibody syndrome(APS) is a well-known clinical syndrome characterized by recurrent arterial or venous thromboses, recurrent fetal loss, thrombocytopenia, together with high titers of sustained anticardiolipin antibody(aCL) or lupus anticoagulant(LA). Although systemic lupus erythematosus(SLB) and APS may coexist, a high proportion of patients manifesting the APS do not suffer from classical lupus or other connective tissue disease. The patient has been defined as having a primary antiphospholipid antibody syndrome. We experienced one case of primary APS with recurrent fetal loss, recurrent cerebral infarctions, positive anticardiolipin antibody IgG and fluttering vegetation on the mitral valve, without other connective tissue diseases including SLE. Forty-three old female had 2 out of 11 criteria for the diagnosis of SLE, such as thrombocytopenia and positive antinuclear antibody, but did not meet whole criteria. The patient was treated with ticlopidine, and anticoagulant therapy was recommended.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.12
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• pp.924-934
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• 2018

This paper describes the development and measurement results of C-band planar active phase array antenna for detecting and tracking radar(weapon-locating radar). The antenna is designed with 14 sub-arrays(12 main channels and 2 sidelobe blanking channels and approximately 3,000 elements of transmit-receive channel) to generate transmit and digital receive patterns. Using a near-field measurements facility, G/N, transmit patterns, and received patterns are measured. Receive patterns are implemented with digital beamforming by signal processing. The measurement results demonstrate that antenna design specifications were fulfilled.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.59-65
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• 2022

In this paper, a digital active phased array antenna is briefly introduced and beam forming method for a dual-channel side-lobe blanking applied to blank the side-lobe of the main beam is described. Next, the antenna performance was verified from results of design and antenna near-field measurement for the antenna main beam and side-lobe blanking beam. Then, a single-channel side-lobe blanking beam forming method was proposed to reduce the number of channels than the existing system operating dual-channel side-lobe blanking beam and weight distribution for each element of the side-lobe blanking antenna was designed with the proposed method. Finally, the designed single-channel side-lobe blanking beam pattern and blanking ability were verified and compared with the dual-channel side-lobe blanking beam. In addition, by comparing/verifying the conventional dual-channel and the proposed single-channel side-lobe blanking beam patterns measured through the receiving near-field test of the digital active phased array antenna and their ability to blank side-lobe of the main beam, validity of the proposed method for forming single-channel side-lobe blanking beam was confirmed.

• Tuberculosis and Respiratory Diseases
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• v.58 no.6
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• pp.570-575
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• 2005

Introduction : Diffuse interstitial lung diseases (DILD) comprise of a large group of lung diseases with diverse etiologies. They are classified into four categories based on the etiology and pathological findings. In Korea, epidemiological data on DILD has never been reported in a prospective manner. Method : From May 2002 to April 2004, total 487 patients with DILD were prospectively registered at Samsung Medical Center. The prospective observational analysis of the etiologies, its classification based on 2002 ATS/ERS (American Thoracic Society/European Respiratory Society) guidelines, as well as diagnostic tests and the retrospective analysis of the treatment modalities were carried out. Any infectious and malignant causes were excluded. Results : 1) The patients were classified into idiopathic interstitial pneumonia (IIP) in 269 patients (55.2%), known causes of DILD in 168 patients (34.5%), sarcoidosis in 27 patients (5.5%), other forms of DILD in 14 patients (2.9%), and undetermined DILD in 9 patients (1.9%). 2) The diagnostic test showed that most patients had undergone chest high resolution computed tomography (HRCT) and pulmonary function test (PFT) (97%, 89%). Transbronchial lung biopsy (TBLB) and surgical lung biopsy (SLB) were performed in limited patients (38%, 29%). 3) Among 269 patients with IIP, 220 (82%) had idiopathic pulmonary fibrosis (IPF) while 23 (9%) had nonspecific interstitial pneumonia. SLB was carried out in 36% of patients with IIP. 4) Symptomatic supportive care was given to 67% of IPF, but specific medical treatment including corticosteroids was administered to 89% of non-IPF patients. Conclusion : A nationwide registry of DILD patients is required to determine the annual incidence, etiology, and practice pattern of diagnosis and treatment in Korea.