• Restorative Dentistry and Endodontics
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• 제42권3호
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• pp.224-231
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• 2017

Objectives: To determine the actual revolutions per minute (rpm) values and compare the cyclic fatigue life of Reciproc (RPC, VDW GmbH), WaveOne (WO, Dentsply Maillefer), and TF Adaptive (TFA, Axis/SybronEndo) nickel-titanium (NiTi) file systems using high-speed camera. Materials and Methods: Twenty RPC R25 (25/0.08), 20 WO Primary (25/0.08), and 20 TFA ML 1 (25/0.08) files were employed in the present study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which has an artificial stainless steel canal with a $60^{\circ}$ angle of curvature and a 5-mm radius of curvature. The files were divided into 3 groups (group 1, RPC R25 [RPC]; group 2, WO Primary [WO]; group 3, TF Adaptive ML 1 [TFA]). All the instruments were rotated until fracture during the cyclic fatigue test and slow-motion videos were captured using high-speed camera. The number of cycles to failure (NCF) was calculated. The data were analyzed statistically using one-way analysis of variance (ANOVA, p < 0.05). Results: The slow-motion videos were indicated that rpm values of the RPC, WO, and TFA groups were 180, 210, and 425, respectively. RPC ($3,464.45{\pm}487.58$) and WO ($3,257.63{\pm}556.39$) groups had significantly longer cyclic fatigue life compared with TFA ($1,634.46{\pm}300.03$) group (p < 0.05). There was no significant difference in the mean length of the fractured fragments. Conclusions: Within the limitation of the present study, RPC and WO NiTi files showed significantly longer cyclic fatigue life than TFA NiTi file.

• 한국태양에너지학회 논문집
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• 제30권5호
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• pp.44-55
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• 2010

The proposed offshore wind farm projects, i.e., Mooudo offshore, Yeonggwang-Gochang offshore, Saemangeum offshore, Imjado offshore and Gadeokdo-Dadeapo offshore, were compared and analyzed using the Korea National Wind Mapand Wind Farm Suitability Assessment System developed by the Korea Institute of Energy Research. The suitability of the proposed areas was comprehensively assessed using geographic, economic constraints, wave condition and wind resource factors, but the focus of this paper was on the geographic constraints and wave conditions. Imjado had several geographical constraints, despite having a good wind power density, while Saemangeum had a relatively low wave height, shallow water depth, close substation and slow tidal current. It is anticipating that the present comparison and analysis could be used as reference guidelines when selecting and preparing the design of large-scale offshore wind farm in the near future.

• 천문학회보
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• 제43권1호
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• pp.56.3-56.3
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• 2018

The present study formulates the theory of spontaneously emitted electromagnetic fluctuations in magnetized plasmas containing particles with an anisotropic suparthermal (bi-Kappa) velocity distribution function. The formalism is general applying for an arbitrary wave vector orientation and wave polarization, and for any wave-frequency range. As specific applications, the high-frequency electromagnetic fluctuations emitted in the upper-hybrid and multiple harmonic electron cyclotron frequency range are evaluated. The fluctuations for low-frequency are also applied, which include the kinetic $Alfv\acute{e}n$, fast magnetosonic/whistler, kinetic slow mode, ion Bernstein cyclotron modes, and higher-order modes. The model predictions are confirmed by a comparison with particle-in-cell simulations. The study describes how energetic particles described by kappa velocity distribution functions influence the spectrum of high and low frequency fluctuations in magnetized plasmas. The new formalism provides quantitative analysis of naturally occurring electromagnetic fluctuations, and contribute to an understanding of the electromagnetic fluctuations observed in space plasmas, where kappa-distributed particles are ubiquitous.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1998년도 추계학술발표 논문집
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• pp.154-157
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• 1998

This study investigated the psychological and physiological responses to the sound of car horns produced by different. manufacturers. Ten female college students listened to the sound of the horns while their EEG responses on 6 sites were being measured, and rated each hem on psychological scales. Their EEG and psychological responses were investigated as to whether the responses were related to the loudness, sharpness, tonality, and roughness of the horns. The results indicated that the subjects felt more 'dominated' as the loudness and sharpness increased, that the subjects felt more 'pleasant' as the sharpness increased, that the subjects felt more 'dominant' as the tonality increased, and that the subjects felt more 'aroused' as the roughness increased. The physiological results showed that the fast alpha wave in the occipital lobe decreased in the relative power as the loudness, sharpness, and tonality increased, and that the delta wave in the occipital lobe increased and the slow alpha wave in the frontal lobe decreased in the relative power as the roughness increased.

• Journal of electromagnetic engineering and science
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• 제10권4호
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• pp.322-327
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• 2010

Spaceborne sparse array radar for ground moving targets indication (GMTI) has outstanding advantage over full array radar for constructing ultra-large aperture. Rapid development of millimeter wave (MMW) technology make it possible for realizing MMW GMTI radar, which is much more sensitive to slow moving ground target. The paper presented the system model of a multi-carrier frequency sparse array MMW radar as well as preliminary simulation results, which showed future application of the system is very promising.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.3-5
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• 1996

Electrogastrography(EGG) is the technique by which gastric myoelectrical activity is recorded noninvasively, from electrodes on the abdominal skin. This gastric myoelectrical activity consists of two type signals : 1) slow wave, which is gastric basal rhyemic activity and is not closely related to gastric contraction 2) spike wave, which is generated only during contraction of the stomach. Despite many attempts made over the decades, analysis of surface EGG has not led to identification of the spike wave (gastric contraction) that would help the clinician to diagnose functional or organic diseases of the stomach. In this paper, we propose a feasible methods to detect gastric contraction by frequency-domain signal analysis of surface ECG signal. Synchronous measurement of gastric pressure by the antropyloric manometry with surface EGG established feasibility of this method.

• Journal of Genetic Medicine
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• 제19권2호
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• pp.100-104
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• 2022

The gene encoding solute carrier family 9 member 6 (SLC9A6) on Xq26.3 is associated with Christianson syndrome (CS) mimicking Angelman syndrome. In CS, developmental and epileptic encephalopathy (DEE) appears in about 20%, and DEE with spike-and-wave activation in sleep (SWAS) is reported only in several cases. A 10-year-old boy with DEE showed multidrug resistant focal seizures from 6 months of age. He had progressive microcephaly, regression, global developmental delay without speech, hyperkinesia, and truncal ataxia; he had a long thin face, esotropia, and happy demeanor. Brain magnetic resonance imaging demonstrated cerebellar atrophy. Electroencephalogram at 7.5 years of age showed nearly continuous diffuse paroxysms in slow wave sleep. The seizures were responsive to corticosteroids for a while. Trio whole exome sequencing exhibited a likely pathogenic variant of SLC9A6 in the proband and his asymptomatic mother: c.1194dup (p.Leu399AlafsTer12). This is a rare case report of CS with DEE-SWAS in a Korean patient.

• 한국해안해양공학회지
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• 제6권4호
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• pp.375-388
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• 1994

폭이 좁은 조파 수조에서 해저지형변환에 대한 이동상실험을 수행할 때, 유체력과 해저지형변환은 파진행 방향으로의 2차원 평면내에 한하는 것으로 가정된다. 그러므로 해저지형이 수조내부 방향으로의 변환 등 3차원적인 형태 등은 대체로 무시되거나 또는 계측시의 평균지형 등으로 대표된다. 본 논문에서는 상당히 미세한 토사로 이루어진 해저지형변환에 대한 이동상실험을 통하여 (1)상대적으로 폭이 좁은 수로내에서 3차원 현상이 발생할 수 있는 지의 여부 및 (2) 3차원 현상 발생에 대한 여러 가지 원인 및 그들의 상관 관계 등을 조사하였다. 그 결과 유체력과 해저지형변환간에 서서히 발생하는 상호 간섭(slow feedback)을 통하여 해저지형의 수로내 폭 방향으로의 변환 등 3차원적인 형상 등이 발생 성장되며, 위 현상은 해저지형이 그 변환단계에 있어 평형상태(equilibrium)에 접근할 때 쉽게 발생한다는 것을 알게 되었다.

• 말소리와 음성과학
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• 제13권4호
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• pp.47-53
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• 2021

Autoregressive한 TTS 모델은 불안정성과 속도 저하라는 본질적인 문제를 안고 있다. 모델이 time step t의 데이터를 잘못 예측했을 때, 그 뒤의 데이터도 모두 잘못 예측하는 것이 불안정성 문제이다. 음성 출력 속도 저하 문제는 모델이 time step t의 데이터를 예측하려면 time step 1부터 t-1까지의 예측이 선행해야 한다는 조건에서 발생한다. 본 연구는 autoregression이 야기하는 문제의 대안으로 end-to-end non-autoregressive 가속 TTS 모델을 제안한다. 본 연구의 모델은 Tacotron 2 - WaveNet 모델과 근사한 MOS, 더 높은 안정성 및 출력 속도를 보였다. 본 연구는 제안한 모델을 토대로 non-autoregressive한 TTS 모델 개선에 시사점을 제공하고자 한다.

• 한국습지학회지
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• 제18권1호
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• pp.84-93
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• 2016

해양과 육지 사이에 있는 연안습지는 연안의 수질을 개선하고 다양한 생물의 자연적인 서식처로 이용될 뿐 아니라 연안침식을 억제하는 기능을 가지고 있다. 연안식생은 외해에서 입사하는 파에너지 또는 폭풍해일을 감소하며 해저 안정화를 통해 습지를 유지하는 기능을 가지고 있다. 식생에 의한 파랑감쇠의 특성을 위해서는 식생과 파랑의 역학적 과정의 검토가 필수적이며 이를 통해 연안과정이나 연안의 동수역학적 특성을 이해할 수 있다. 본 연구에서는 파랑조건 이외에 식생형태에 따른 파랑감쇠 특성을 정량화하기 위해 수리실험을 통해 검토하였으며, 식생모형은 강성식생을 대상으로 규칙파가 작용하는 경우에 대해 파악하였다. 파형경사 ak와 상대수심 kh에 따른 수면위로 돌출된 식생에 대한 파랑감쇠를 검토하기 위하여 수리실험과 수치해석을 수행하였다. 실험결과에 대한 파고감쇠는 Dalrymple et al.(1984)의 파고감쇠식을 통해 식생에 의한 파고전달율, 감쇠율 및 항력계수를 해석하였다. 실험결과 식생에 작용하는 항력계수는 Reynolds수 보다는 Keulegan-Carpenter 수와 상관성이 있고, 파형경사가 증가할수록 파고감쇠율이 증가하고 있음을 확인하였다.