• 지질공학
• /
• 제29권4호
• /
• pp.405-415
• /
• 2019

수압암반절개에서 유도된 균열은 자유면에서 지반의 최소주응력에 수직인 방향인 자유면과 평행한 방향으로 형성되거나, 기존에 발달한 미세균열의 영향을 많이 받는다. 본 연구에서는 흑운모화강암 사면에서 시추공 축과 평행한 방향으로 유도슬롯을 생성하여 이중패커의 압력 및 인터벌 구간에 수압을 주입하는 수압암반절개 실험을 수행하고 그 결과를 분석하였다. 실험 결과, 이중패커 압력 및 인터벌 구간 내의 주입으로 형성된 균열은 유도슬롯 방향을 따라 미세하게 나타났으며, 일부 균열은 시추공을 가로질러 연장되었다. 따라서 수압암반절개는 절개할 방향으로 유도슬롯을 생성하여 보다 많은 유량을 주입하면 효율적인 유도균열 조절이 가능할 것으로 판단된다.

• Journal of Chest Surgery
• /
• 제18권2호
• /
• pp.241-249
• /
• 1985

Twenty-one patients with Double Chambered Right Ventricle [DCRV] associated with Ventricular Septal Defect [VSD] were treated by open heart surgery under cardiopulmonary bypass with moderate hypothermia in the Department of Thoracic and Cardiovascular Surgery, Hanyang University Hospital between June 1982 and October 1984. The following results were obtained 1. The symptoms and physical signs, specific for DCRV, could not be identified. 2. The radiologic findings on simple chest X-ray, specific for DCRV, could not be identified. 3. Electrocardiographic findings, specific for DCRV, could not be identified. 4. Cardiac catheterization was found to be the most important diagnostic method, revealing pressure gradient between proximal chamber and distal chamber in the right ventricle. The average pressure gradient between two chambers showed 48.1523.29 mmHg[varying from 15mmHg to 94mmHg]. 5. Cardiac angiography was found to visualize the anomalous muscle bundles in right ventricle [in 17 cases, 81%] but the evidence of pressure gradient between two chambers within right ventricle is considered necessary for the diagnosis of DCRV. 6. Via surgical observation, anatomical and pathologic findings of the anomalous muscle bundles, associated DCRV were identified. 7. As the direct pressure was measured on the operating table before and after surgery, the average pressure gradient across the muscle bundles showed 40.5219.75mmHg [varying from 16 to 89mmHg] preoperatively and 8.909.72mmHg [varying from 0 to 32mmHg] postoperatively, indicating significant surgical correction of the obstruction present. 8. The presence of anomalous muscle bundles, dividing the right ventricle into two separated chambers, and the presence of the pressure gradient over 15mmHg are considered necessary for the diagnosis of DCRV.

• Steel and Composite Structures
• /
• 제36권2호
• /
• pp.187-196
• /
• 2020

Double skin composite wall system owns several structural merits in terms of high load-carrying capacity, large axial stiffness, and favorable ductility. A recently proposed form of truss connector was used to bond the steel plates to the concrete core to achieve good composite action. The structural behavior of rectangular high walls under compression and T-shaped high walls under eccentric compression has been investigated by the authors. Furthermore, the influences of the truss spacings, the wall width, and the faceplate thickness have been previously studied by the authors on short walls under uniform compression. This paper experimentally investigated the effect of width-to-thickness ratio on the compressive behavior of short walls. Compressive tests were conducted on three short specimens with different width-to-thickness ratios. Based on the test results, it is found that the composite wall shows high compressive resistance and good ductility. The walls fail by local buckling of steel plates and crushing of concrete core. It is also observed that width-to-thickness ratio has great influence on the compressive resistance, initial stiffness, and strain distribution across the section. Finally, the test results are compared with the predictions by modern codes.

• 한국수산과학회지
• /
• 제25권6호
• /
• pp.457-473
• /
• 1992

양향성 대륙붕에서 1차 파동방정식은 양 해안경계에서의 바람응력과, 대륙붕폭에 걸친 바람응력의 회전효과를 갖는다. 황해에서 바람응력 회전효과는 대륙붕파를 발생시키는 힘으로서 무시될 수 있다. 켈빈파는 대륙붕파보다 약화될 때까지의 거리가 매우 크기 때문에 황해 북쪽만(별)을 거의 약화되지 않고 통과할 수 있다. 파동특성을 따라 적분하는 수치방법은 반대방향으로 전파되는 파동을 수용하기 위해 조절되었다. 보다 실제와 가까운 해안선을 사용한 결과, 모델재생이 해류에서는 개선되었으나 해수면에서는 거의 개선되지 않았다. 이것은 해수면을 주로 결정하는 켈빈파가 해저지형의 변화에 영향을 극히 적게 받음을 의미한다 보다 개선된 해수면 재생을 위해서는 동지나 해에서 황해로 전파되는 켈빈파의 에너지를 알 필요가 있다. 해안을 따른 순풍류와 골을 따른 역풍류의 기본구조는 계절풍에 의해 발생하는 황해의 계절순환을 뒷받침한다.

• Archives of Plastic Surgery
• /
• 제44권1호
• /
• pp.53-58
• /
• 2017

Background Adequate fixation of replanted digits is essential not only for short-term healing but for long-term function. Various bony fixation methods using Kirschner (K-) and intraosseous wire are available in replantation. We examined clinical and radiographic outcomes of fixation methods on bone union after digital replantation. Methods A single institutional retrospective review identified 992 patients who had undergone 1,247 successful replantations between July 2009 and September 2015. Exclusion criteria included amputations of the distal phalanx, comminuted fractures, and intra-articular fractures. Patients were classified according to 5 categories of fixation methods: single K-wire, double longitudinal K-wires, cross K-wires, wire with, and wire without K-wire support. Bone union was evaluated by 5-month postoperative X-ray and fixation outcomes were compared across the 5 groups. Results The exclusion criteria were applied, and 88 patients with 103 replanted digits remained for analysis. Single K-wire fixation was used in 40 digits, double longitudinal K-wires in 30, and cross fixation in 14. Wire with and without K-wire support was required in 15 and 4 digits. Nonunion was observed in 32 digits (31.1%), of which 13 required additional operations such as bone graft or corrective osteotomy. The highest percent of nonunion was observed after cross fixation (35.7%) and the lowest after wire alone (25.0%). Conclusions In this study, contrary to general knowledge, we found that single K-wire fixation was not associated with poorer outcomes. Successful bone union outcomes may be achieved by careful selection of bone fixation methods. This study provides useful information for planning bone fixation in digital replantation.

• 한국음향학회지
• /
• 제39권5호
• /
• pp.476-482
• /
• 2020

입력열과 출력열의 길이가 다른 경우 attention 기법을 이용한 sequence-to-sequence 심층 신경망이 우수한 성능을 보인다. 그러나, 출력열의 길이에 비해서 입력열의 길이가 너무 긴 경우, 그리고 하나의 출력값에 해당하는 입력열의 특성이 변화하는 경우, 하나의 문맥 벡터(context vector)를 사용하는 기존의 attention 방법은 적당하지 않을 수 있다. 본 논문에서는 이러한 문제를 해결하기 위해서 입력열의 왼쪽 부분과 오른쪽 부분을 각각 개별적으로 처리할 수 있는 두 개의 문맥 벡터를 사용하는 이중 attention 기법을 제안한다. 제안한 방법의 효율성은 TIMIT 데이터를 사용한 음성 인식 실험을 통하여 검증하였다.

• 한국균학회지
• /
• 제26권3호통권86호
• /
• pp.387-395
• /
• 1998

여러가지 기주에서 유쾌한 Calonectria ilicicola 균주의 병원성에 대한 형태적, 유전적 표지를 검출하기 위하여 균사생장, 균핵, 자낭각 그리고 dsRNA를 조사하였다. 시험된 모든 균주에서 병원성, 균핵수, 자낭각수 와 균사생장 등의 다양한 변이가 관찰되었으나 dsRNA는 검출되지 않았다. 균의 병원성은 균핵과 자낭각 생산과 각각 정의 상관관계가 있었으나, 균사 생장은 자낭각의 생산과 부의 상관관계를 보여 주었다. 땅콩에서 유래한 균주보다 콩에서 유래한 균주가 기주인 콩에 더 강한 병원성을 보였으며 균핵과 자낭각의 생산도 더 많았다. 이와 같은 결과로 볼 때 C. ilicicla의 균핵과 자낭각 생산력은 inoculum potential의 구성요소로써 작용하며, 이중 균의 자낭각 생산력은 병원성과 기주 분화를 나타내는데 유용한 표지로써 이용될 수 있을 것이다.

• International journal of advanced smart convergence
• /
• 제11권4호
• /
• pp.96-103
• /
• 2022

This paper presents the analysis of increasing the resolution of True-Time-Delay (TTD) by 0.5-bit for phased-array antenna system which is one of the Multiple-Input and Multiple Output (MIMO) technologies. For the analysis, a 5.5-bit True-Time Delay (TTD) integrated circuit is designed and analyzed in terms of beam steering performance. In order to increase the number of effective bits, the designed 5.5-bit TTD uses Single Pole Triple Throw (SP3T) and Double Pole Triple Throw (DP3T) switches, and this method can minimize the circuit area by inserting the minimum time delay of 0.5-bit. Furthermore, the circuit mostly maintains the performance of the circuit with the fully added bits. The idea of adding 0.5-bit is verified by analyzing the relation between the number of bits and array elements. The 5.5-bit TTD is designed using 0.18 ㎛ RF CMOS process and the estimated size of the designed circuit excluding the pad is 0.57×1.53 mm². In contrast to the conventional phase shifter which has distortion of scanning angle known as beam squint phenomenon, the proposed TTD circuit has constant time delays for all states across a wide frequency range of 4 - 20 GHz with minimized power consumption. The minimum time delay is designed to have 1.1 ps and 2.2 ps for the 0.5-bit option and the normal 1-bit option, respectively. A simulation for beam patterns where the 10 phased-array antenna is assumed at 10 GHz confirms that the 0.5-bit concept suppresses the pointing error and the relative power error by up to 1.5 degrees and 80 mW, respectively, compared to the conventional 5-bit TTD circuit.

• ETRI Journal
• /
• 제42권1호
• /
• pp.46-53
• /
• 2020

Gait analysis is an effective clinical tool across a wide range of applications. Recently, inertial measurement units have been extensively utilized for gait analysis. Effective gait analyses require good estimates of heel-strike and toe-off events. Previous studies have focused on the effective device position and type of triaxis direction to detect gait events. This study proposes an effective heel-strike and toe-off detection algorithm using a smart insole with inertial measurement units. This method detects heel-strike and toe-off events through a time-frequency analysis by limiting the range. To assess its performance, gait data for seven healthy male subjects during walking and running were acquired. The proposed heel-strike and toe-off detection algorithm yielded the largest error of 0.03 seconds for running toe-off events, and an average of 0-0.01 seconds for other gait tests. Novel gait analyses could be conducted without suffering from space limitations because gait parameters such as the cadence, stance phase time, swing phase time, single-support time, and double-support time can all be estimated using the proposed heel-strike and toe-off detection algorithm.

• Journal of Astronomy and Space Sciences
• /
• 제37권2호
• /
• pp.77-84
• /
• 2020

We performed high-resolution three-dimensional global magnetohydrodynamic (MHD) simulations to study the interaction between the Earth's magnetosphere and a prolonged steady southward interplanetary magnetic field (IMF) (Bz = -2nT) and slow solar wind. The simulation results show that dayside magnetic reconnection continuously occurs at the subsolar region where the magnetosheath magnetic field is antiparallel to the geomagnetic field. The plasmoid developed on closed plasma sheet field lines. We found that the vortex was generated at the magnetic equator such as (X, Y) = (7.6, 8.9) R_E due to the viscous-like interaction, which was strengthened by dayside reconnection. The magnetic field and plasma properties clearly showed quasiperiodic variations with a period of 8-10 min across the vortex. Additionally, double twin parallel vorticity in the polar region was clearly seen. The peak value of the cross-polar cap potential fluctuated between 17 and 20 kV during the tail reconnection.