• 한국인터넷방송통신학회논문지
• /
• 제19권3호
• /
• pp.149-155
• /
• 2019

본 논문에서는 Ka-대역 수동위상배열탐색기에 적용할 위상 변위기를 설계하고 제작하여 성능을 확인하였다. 수동위상배열안테나에서 배열소자의 위상을 조절하여 전자 빔 조향을 수행하기 위한 핵심 소자인 위상 변위기를 설계하여 Ka-대역 1GHz 대역폭내에서 삽입손실 1.5dB이하 위상 오차 $10^{\circ}$(RMS)이내의 성능을 확인하였다. 실제 제작을 통해 확인된 성능은 배열합성 이론에 기초한 빔패턴 분석에 적용하여 추가적인 분석을 수행하였다. 검증된 위상 변위기의 최종 성능이 수동위상배열안테나 빔패턴의 성능 및 지향 오차, 각도 정확도에 미치는 영향성을 분석하여 제안된 위상 변위기 규격의 유효성을 검증하였다.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
• /
• 제61권12호
• /
• pp.663-668
• /
• 2018

Background and Objectives The main objectives of this study were to determine the clinical usefulness of the program-assisted and real ear measurement (REM)-assisted fitting of hearing aids. Subjects and Method Fifteen participants with moderate to moderately severe hearing loss were enrolled in this study. Objective and subjective fitting results were assessed to compare the benefits between the program-assisted fitting (using a software fitting program) and the REM-assisted fitting. Real ear insertion gain (REIG), sound-field audiometry using warble tone, and Korean Hearing in Noise Test (K-HINT) were performed as objective tests. Sound quality rating was performed as a subjective test. Results In the program fitting, 48.89% of fitting points failed to come within ${\pm}10dB$ of the REIG target. In the REM fitting, however, the percentage of failure significantly decreased to 23.33% (p=0.013). In K-HINT test, the reception threshold for speech in quiet situation significantly decreased from 50.1 dB HL with the program fitting to 44.7 dB HL after the REM fitting (p<0.001). In front noise condition, signal-to-noise ratio improved from 4.53 dB to 3.50 dB with the REM fitting without statistical significance (p=0.099). In the sound quality rating, the REM fitting ($4.27{\pm}0.56$) showed a significantly better sound quality ratings than the program fitting ($3.69{\pm}0.74$) (p=0.017). Conclusion The REM fitting showed better results in both subjective and objective measurements than the program fitting.

• 한국연극학
• /
• 제52호
• /
• pp.159-188
• /
• 2014

Under the influence of postmodernism, modern writing tends to refuse an immediate conveyance of messages achieved by linear, unified writing. Such writing does not attempt any social participation and has no leading ethics, offering diverse perspectives. It simply relies on material property ignoring the 'here and now'. This discussion depends on the sensuous immediacy of works that are pure and uninterpretable, causing the "death of author" phenomena. Although the time was late, since the 1990s, discussion and work on deconstructive theater has been executed in the Korean theater world. This deconstructive work was achieved when lineal narratives were shattered through the shocking insertion of fragmentary episodes and imagery. Moreover, such plays were shocking presentations of severance in conversation; lack of communication; loss of pride and love; and a world devastated by violence and madness. In the 2000s, such a movement helped form a new paradigm in the theater through reinterpretation and parody of traditional dramas, while drawing general attention to postmodern theater. However, as the problems of postmodern theater are perceived through study, the limit of plays with a postmodern tendency is pointed out: such plays merely display 'deconstruction'. This thesis will examine reflective thought on postmodern theater seeking "deconstruction without alternatives" and the aesthetic concept of "le politique" by Jacques Ranciere. It will also look through the overlap of images as interval-estrangement, "lettre morte", and simulacre representing mise-en-scene aesthetics weaving "political writing". This study is meaningful in that it tries to extend the new aesthetic horizon of Korean theater, examining in 2009 and by Koh Sun-Woong in 2011, directed by Park Chung-Hee in 2010 and directed by Park Keun-Hyung in 2009.

• Clinics in Shoulder and Elbow
• /
• 제22권1호
• /
• pp.29-36
• /
• 2019

Background: The execution of fibular allograft augmentation in unstable proximal humerus fractures (PHFs) was technically demanding. In this study, the authors evaluated the clinical and radiographic outcomes after tricortical iliac allograft (TIA) augmentation in PHFs. Methods: We retrospectively assessed 38 PHF patients treated with locking-plate fixation and TIA augmentation. Insertion of a TIA was indicated when an unstable PHF showed a large cavitary defect and poor medial column support after open reduction, regardless of the presence of medial cortical comminution in preoperative images. Radiographic imaging parameters (humeral head height, HHH; humeral neck-shaft angle, HNSA; head mediolateral offset, HMLO; and status of the union), Constant score, and range of motion were evaluated. Patients were grouped according to whether the medial column support after open reduction was poor or not (groups A and B, respectively); clinical outcomes were compared for all parameters. Results: All fractures healed radiologically (average duration to complete union, 5.8 months). At final evaluation, the average Constant score was 73 points and the mean active forward flexion was $148^{\circ}$. Based on the Paavolainen assessment method, 33 patients had good results and 5 patients showed fair results. The mean loss of reduction was 1.32 mm in HHH and 5.02% in HMLO. None of the parameters evaluated showed a statistically significant difference between the two groups (poor and not poor medial column support). Conclusions: In unstable PHFs, TIA augmentation can provide good clinical and radiological results when there are poor medial column support and a large cavitary defect after open reduction.

• The Journal of Advanced Prosthodontics
• /
• 제11권3호
• /
• pp.147-154
• /
• 2019

PURPOSE. This study aimed to evaluate the effect of two different implant-abutment connection structures with identical implant design on peri-implant bone level. MATERIALS AND METHODS. This clinical study was a patient-blind randomized controlled trial following the CONSORT 2010 checklists. This trial was conducted in 24 patients recruited between March 2013 and July 2015. Implants with internal friction connection were compared to those with external hex connection. One implant for each patient was installed, replacing the second molar. Implant-supported crowns were delivered at four months after implant insertion. Standardized periapical radiographs were taken at prosthesis delivery (baseline), and one year after delivery. On the radiographs, distance from implant shoulder to first bone-to-implant contact (DIB) and peri-implant area were measured, which were the primary and secondary outcome, respectively. RESULTS. Eleven external and eleven internal implants were analyzed. Mean changes of DIB from baseline to 1-year postloading were 0.59 (0.95) mm for the external and 0.01 (0.68) mm for the internal connection. Although no significant differences were found between the two groups, medium effect size was found in DIB between the connections (Cohen's d = 0.67). CONCLUSION. Considering the effect size in DIB, this study suggested the possibility of the internal friction connection structure for more effective preservation of marginal bone.

• 한국음향학회지
• /
• 제38권2호
• /
• pp.193-199
• /
• 2019

본 논문에서는 선체부착형 음향센서의 플랫폼 진동유기 소음 차단 특성을 확인하기 위한 수중 진동 실험을 수행하고 결과를 분석하였다. 음향수조 환경에서 음향센서가 설치된 선체모사구조물과 가진기를 이용하여 플랫폼 진동유기 소음 조건을 구현하였고, 선체모사구조물 및 음향센서에 설치된 표준 가속도계와 음향센서의 출력신호 측정을 통해 음향센서의 진동차단율, 삽입손실 및 진동민감도와 같은 성능지수를 산출하였다. 산출된 성능지수 결과를 토대로 음향센서의 주파수별 소음 차단 특성을 분석하고 실험 기법의 유효성을 검토하였다.

• 한국미생물·생명공학회지
• /
• 제47권1호
• /
• pp.25-33
• /
• 2019

Lactobacillus rhamnosus BFE5264, isolated from a Maasai fermented milk product ("kule naoto"), was previously shown to exhibit bile acid resistance, cholesterol assimilation, and adhesion to HT29-MTX cells in vitro. In this study, we re-annotated and analyzed the previously reported complete genome sequence of strain BFE5264. The genome consists of a circular chromosome of 3,086,152 bp and a putative plasmid, which is the largest one identified among L. rhamnosus strains. Among the 2,883 predicted protein-coding genes, those with carbohydrate-related functions were the most abundant. Genome analysis of strain BFE5264 revealed two consecutive CRISPR regions and no known virulence factors or antimicrobial resistance genes. In addition, previously known highly variable regions in the genomes of L. rhamnosus strains were also evident in strain BFE5264. Pairwise comparison with the most studied probiotic strain L. rhamnosus GG revealed strain BFE5264-specific deletions, probably due to insertion sequence-mediated recombination. The latter was associated with loss of the spaCBA pilin gene cluster and exopolysaccharide biosynthetic genes. Comparative genomic analysis of the sequences from all available L. rhamnosus strains revealed that they were clustered into two groups, being within the same species boundary based on the average nucleotide identities. Strain BFE5264 had a sister group relationship with the group that contained strain GG, but neither ANI-based hierarchical clustering nor core-gene-based phylogenetic tree construction showed a clear distinctive pattern associated with the isolation source, implying that the genotype alone cannot account for their ecological niches. These results provide insights into the probiotic mechanisms of strain BFE5264 at the genomic level.

• 한국인터넷방송통신학회논문지
• /
• 제21권1호
• /
• pp.107-114
• /
• 2021

본 논문에서는 새롭게 제안되는 L-형 모노폴 슬롯 공진기를 이용한 X-band용 평면형 트랜지스터 발진기를 제안하였다. 평면형 설계를 위해 끝이 개방된 L자형 모노폴 슬롯을 트랜지스터 발진기의 공진기로 사용하였다. 3단계를 통한 공진기의 모의 실험 설계 결과 1169.84의 높은 Q 값과 49.934 dB의 높은 삽입 손실을 확인하였다. 최종 설계 및 제작된 발진기의 측정결과 7 dBm 이상의 발진 출력과 100 kHz 오프셋에서 - 58 dBc/Hz의 양호한 위상 잡음 특성을 가지는 것을 확인하였다. 제안된 발진기는 평면형으로 마이크로파 집적회로 기술에 직접 적용할 수 있다는 장점을 가지고 있다. 또한 DRO(유전체 공진 발진기)의 경우처럼 3D 구조의 금속 공동, 튜닝 스크류 등 추가 기기 없이 마이크로스트립 형태로만 구현할 수 있어 크기를 줄일 수 있다는 장점도 있다.

• 한국정보전자통신기술학회논문지
• /
• 제13권6호
• /
• pp.483-488
• /
• 2020

최근에는 수요자의 다양한 요구를 충족하는 서비스를 제공하기 위해서 여러 개의 무선통신 시스템을 하나로 통합한 무선기기에 대한 수요가 증가하고 있다. 다양한 무선통신 시스템으로 구성된 무선기기에는 많은 주파수 고정형 필터가 필요하다. 주파수 가변 필터는 다수의 주파수 고정형 필터를 대체할 수 있으며, 주파수 가변 필터를 사용하면 시스템을 보다 효율적으로 구성할 수 있다. 본 논문에서는 800 ~ 2400MHz 대역에서 동작하는 3-폴 주파수 가변 대역통과필터(BPF)를 설계하였다. 주파수 가변범위를 넓히기 위해서 튜닝 스크류는 스텝을 갖도록 설계하였고, 튜닝 스크류의 조절을 용이하게 하기 위해서 리니어 모터를 사용하였다. 구현한 주파수 가변 BPF는 설계한 주파수 범위에서 동작하며, 삽입손실은 최대 2.82dB, 중심주파수에서 ± 50MHz 이격된 지점에서 최소 18.7dB의 감쇠 성능을 갖는다.

• 한국인터넷방송통신학회논문지
• /
• 제22권2호
• /
• pp.35-42
• /
• 2022

본 논문에서는 SSPA(Solid state amplifier) 의 핵심 모듈인 결합기의 효율 및 격리 특성을 높이는 방법에 대해 연구하였다. 구체적으로 도파관 결합기에서 공용 포트와 격리 포트 정합을 이루어 격리도를 확보 하였다. 정합을 위한 매칭 구조는 원형 디스크 형태로 도파관 결합기 내부에서 음각으로 가공하게 된다. 구조는 매우 단순하여 안정적인 성능 확보가 가능하다. 그리고 이러한 구조는 이전 연구 대비 60배 이상의 높은 임계전력 성능을 보여 고출력에 적합함을 확인하였다. 그리고 1단의 T-junction과 2, 3단의 MagicT 결합기를 조합하여 소형화를 이루고, 삽입손실을 줄여 결합 효율을 최적화 하였다. 제작된 도파관 결합기는 16dB 이상의 격리도와 86.2% 의 결합 효율을 얻었다.