Earticle

Quantum information processing using superconducting qubit based on Josephson junction has become one of the most promising candidates for possible realization of a quantum computer. In the heart of the qubit circuits, the superconducting microwave resonator plays a key role in quantum operations and measurements, which enables single- photon level microwave quantum optics. During last decade, the coherence time, or the lifetime of the quantum state, of the superconducting qubit has been dramatically improved. Among several technological innovations, the improvement of superconducting microwave resonator’s quality has been the main driving force in getting the qubit performance almost ready for elementary quantum computing architecture. In this paper, I will briefly review very recent progresses of the superconducting microwave resonators especially aimed for quantum device applications during the last decade. The progresses have been driven by ingenious circuit design, material improvement, and new measurement techniques. Even a rather radical idea of three-dimensional large resonators have been successfully implemented in a qubit circuit. All those efforts contributed to our understanding of the qubit decoherence mechanism and as a result to the improvement of qubit performance.

본 논문에서는 五行[1]의 상보성원리를 위상 간섭제거에 응용했다. 상생과 상극개념을 송신과 수신의 직접신호와 간섭신호에 대응시켰다. 五行(5 prime substances : 5 user networks)과 같은 네트워크 토폴로지(topology)를 제안한다. 전송된 신호의 할당 가능성을 조절 및 간섭 할당 방법을 잘 선택해, 최적의 대칭 DoF(degree of freedom)가 다른 채널동기 시간의 5 user 네트워크 달성이 가능함을 설명한다. 이론적으로는 5 user 네트워크가 무선 이동 채널 환경에 잘 match 된다는 결과를 보이고, 제안한 네트워크가 무선 네트워크 응용에 적용될 수 있음을 보여주는 다른 채널 동기 시간에 대해 대칭 DoF를 달성함을 보인다. 5 user 네트워크 토폴로지에서 modulo 3 성능을 이용하면 송신기 협력이 간섭 할당 방법으로 2/3의 DoF를 보다 쉽게 달성할 수 있다.

In this paper, we apply the complementation principle of five prime substances to reduce the phase interference. The transmitter and receiver match the concepts of co-operative and conflict to the direct and indirect signals. The result shows we investigate the proposed network topology such as 5 prime substances (5 user networks). The key observation is that optimal symmetric degree of freedom (DoF) can be achieved for 5 user network with different channel coherence times by adaptively selecting the interference alignment scheme via controlling the alignment feasibility of the transmitted signals. Theoretical results demonstrate the effectiveness of the proposed 5 user networks are well matched to the wireless mobile channel environment to achieve the symmetric DoF for different channel coherence times which ensures that the proposed networks are applicable for dense wireless network applications. Modulo 3 functionality in 5 user network topology makes it easier for the transmitter cooperation to achieve the DoF of 2/3 with the help of the interference alignment schemes.

Through a “genotextual” investigation of the works of Fernando Vallejo(1942, Medellín, Colombia), we discover the conscious and deliberatemechanismthat the hybrid, boundary-relativizing nature of El río del tiempo [River of Time]auto-fictional form obeys. There appear factors that seem to have beenneglected by the unwary reader in a lapsed moment, but at the same time thatexploit the supposedly author, and have contributed to the association of Vallejo’sname and that of his character “Fernando” as cursed. The present work isdedicated to understanding these and other related factors such as thecoherence. Within its pages, we can see how the writing, as the development orproduction of the subject, and as a reflection on life, overlaps itself in acompositional game played via mechanisms of memory and ambiguity whichtransform into something that defines his auto-fiction, but that at the same timeremains an exploitable resource, turning the writing into a space for reflection(“decir” and “hacer”) and into ameans of liberation fromall sorts of potentialitiesand determinisms (mythical, sociopolitical, religious, and other discursivegenres).

Al indagar en la obra del escritor Fernando Vallejo (1942, Medellín,Colombia), desde un orden “genotextual”, notamos cómo el carácter híbrido dela forma “autoficcional” que subyace a la relativización de fronteras en El río deltiempo obedece a un mecanismo consciente y deliberado. Un factor del que sesirve el autor, pero que parece no haber sido atendido por el lector incauto, y hacontribuido a asociar su nombre y el de su personaje “Fernando” a figura maldita. A la comprensión de estos y otros factores asociados tales como la coherencia,apunta el presente trabajo donde vemos que la escritura en tanto produccióndel sujeto y reflejo de vida se imbrican en un juego composicional articulado porlos mecanismos de la memoria y la ambigüedad que se convierten endefinitorios de su autoficción, pero también en un recurso que explota para hacerde la escritura un espacio de reflexión (“ decir” y “hacer”) y un medio deliberación frente a todo tipo de poderes o determinismos (míticos, sociopolíticos,religiosos y géneros discursivos).

Al indagar en la obra del escritor Fernando Vallejo (1942, Medellin,Colombia), desde un orden “genotextual”, notamos como el caracter hibrido dela forma “autoficcional” que subyace a la relativizacion de fronteras en El rio deltiempo obedece a un mecanismo consciente y deliberado. Un factor del que sesirve el autor, pero que parece no haber sido atendido por el lector incauto, y hacontribuido a asociar su nombre y el de su personaje “Fernando” a figura maldita. A la comprension de estos y otros factores asociados tales como la coherencia,apunta el presente trabajo donde vemos que la escritura en tanto producciondel sujeto y reflejo de vida se imbrican en un juego composicional articulado porlos mecanismos de la memoria y la ambiguedad que se convierten endefinitorios de su autoficcion, pero tambien en un recurso que explota para hacerde la escritura un espacio de reflexion (“decir” y “hacer”) y un medio deliberacion frente a todo tipo de poderes o determinismos (miticos, sociopoliticos,religiosos y generos discursivos).

The purpose of this article is to compare spectral-domain (SD) and time-domain (TD) optical coherence tomography (OCT) findings in patients with solar retinopathy. Complete ocular examinations and OCT were performed in two patients presenting with acute solar retinopathy soon after observation of an eclipse. Both patients were evaluated with SD-OCT and TD-OCT at the same time. SD-OCT demonstrated characteristic defects at the level of the inner and outer segment junction of the photoreceptors in all the affected eyes and decreased reflectiveness of the retinal pigment epithelium layer. TD-OCT images showed unremarkable findings in two eyes with deteriorated visual acuity. SD-OCT improves diagnosis and assessment of the degree and nature of foveal damage in patients with solar retinopathy and may be an important tool for use in identifying foveal damage not detected by TD-OCT. SD-OCT may be preferable to TD-OCT for confirmation or assessment of the degree of foveal damage in patients with solar retinopathy.

In this study, we demonstrated Fourier-domain/swept-source optical coherence tomography (FD/SS-OCT) at a center wavelength of 800 nm for in vivo human retinal imaging. A wavelength-swept source was constructed with a semiconductor optical amplifier, a fiber Fabry-Perot tunable filter, isolators, and a fiber coupler in a ring cavity. Our swept source produced a laser output with a tuning range of 42 nm (779 to 821 nm) and an average power of 3.9 mW. The wavelength-swept speed in this configuration with bidirectionality is 2,000 axial scans per second. In addition, we suggested a modified zero-crossing method to achieve equal sample spacing in the wavenumber (k) domain and to increase the image depth range. FD/SS-OCT has a sensitivity of ~89.7 dB and an axial resolution of 10.4 ${\mu}m$ in air. When a retinal image with 2,000 A-lines/frame is obtained, an acquisition speed of 2.0 fps is achieved.

Purpose: To establish and validate a formula to predict spectral domain (SD)-optical coherence tomography (OCT) retinal nerve fiber layer (RNFL) thickness from time domain (TD)-OCT RNFL measurements and other factors. Methods: SD-OCT and TD-OCT scans were obtained on the same day from healthy participants and patients with glaucoma. Univariate and multivariate linear regression relationships were analyzed to convert average Stratus TD-OCT measurements to average Cirrus SD-OCT measurements. Additional baseline characteristics included age, sex, intraocular pressure, central corneal thickness, spherical equivalent, anterior chamber depth, optic disc area, visual field (VF) mean deviation, and pattern standard deviation. The formula was generated using a training set of 220 patients and then evaluated on a validation dataset of 105 patients. Results: The training set included 71 healthy participants and 149 patients with glaucoma. The validation set included 27 healthy participants and 78 patients with glaucoma. Univariate analysis determined that TD-OCT RNFL thickness, age, optic disc area, VF mean deviation, and pattern standard deviation were significantly associated with SD-OCT RNFL thickness. Multivariate regression analysis using available variables yielded the following equation: SD-OCT RNFL = 0.746 × TD-OCT RNFL + 17.104 (determination coefficient [R2] = 0.879). In the validation sample, the multiple regression model explained 85.6% of the variance in the SD-OCT RNFL thickness. Conclusions: The proposed formula based on TD-OCT RNFL thickness may be useful in predicting SD-OCT RNFL thickness. Other factors associated with SD-OCT RNFL thickness, such as age, disc area, and mean deviation, did not contribute to the accuracy of the final equation.

소채널 소구경 음파검층에서 정확한 속도분석을 하기 위한 연구의 일환으로 다채널 석유검층에서 많이 이용되고 있는 STC 방법을 물성을 달리하는 콘크리트 재질로 제작된 3개의 NX 모형공에서의 3 채널 음파검층에 적용해 보고 그 결과를 분석하였다. 자료취득에 이용한 음원의 주 주파수가 측정된 음파파형 및 진폭스펙트럼 그리고 속도분석기법으로서의 STC 특성에 미치는 영향을 비교 분석하였으며, 적절한 음원의 주 주파수의 선택과 셈블런스 투영을 포함한 STC 기법 적용으로 모드별 속도를 효과적으로 결정할 수 있음을 보였다. 이론적 모형 및 모형 시추공 시험자료를 이용한 STC 기법에 대한 연구 결과, 소구경 천부검층에서 4개의 수진기 조합이 가장 바람직한 것으로 나타났으며, 초동피킹 방법을 효과적으로 병행한다면 3개 수진기에서의 적용도 효과적일 수 있음을 보였다.

Slowness time coherence (STC) technique has been applied to 3-receiver slim hole sonic log using 3 NX sized concrete model holes of different physical properties. We analyzed the effects of different source center frequencies on the wave forms, their amplitude spectra, and their STC results. We could determine the sonic velocity of each mode accurately by the application of STC method with the semblance projection and efficient selection of center frequency. Theoretical model and experimental model hole studies indicate that 4-receiver condition is the most ideal for STC in near surface slim hole sonic log. The result also indicates that favorable STC result can be obtained from three-receiver sonic log provided with the help of the first arrival picking method.

본 연구에서는 코히어런스 분석을 통하여 시각집중 기간 동안 시간 변화에 대한 뇌기능과 관련된 공간-주파수간 연관관계를 해석하였다. 집중관련 시각자극 실험 데이터를 통해 ${\theta}$와 ${\alpha}$ 대역에서 서로 다른 두피 위치간 위상연관변화를 확인하였다. 좌우 전두엽, 전두엽과 두정엽 간 뇌유발전위는 P100, N200지점에서 위상동조를 보였으며, 전두엽과 후두엽 간 뇌유발전위는 시각 처리 정보가 반영되는 P300지점에서 위상동조를 보였다. 고정된 길이의 창을 이용하는 단구간 푸리에 변환에 비하여 연속 웨이블릿 변환은 모 웨이블릿의 파라미터 조정을 통한 다중해상도 분석이 가능하였다. 따라서 연속 웨이블릿 변환을 이용한 코히어런스 결과가 시간변화에 대한 뇌유발전위의 공간-주파수간 연관관계의 변화를 확인하는데 유효함을 확인하였다. 비 집중 자극수행에 대해서는 위상동조 현상이 나타나지 않았다.

In this study, we analyzed spatial-frequency relationship related brain function for change of the time during attentional visual stimulus through the analysis of Coherence. With experimentation about ERP(Event Related Potential)data, it revealed that change of the phase synchronization between different scalp locations at ${\theta}$, ${\alpha}$ band. ERP between left and right frontal lobes, between the frontal and central lobes showed the phase synchronization at the P100, N200, ERP between the frontal and occipital lobes showed the phase synchronization at the P300 related information of visual stimulus. Compared to STFT using the window of a fixed length, CWT is able to multi-resolution analysis with the adjustment of parameters of mother wavelet. Thus, coherence results with CWT was found to be effective for analysis of time-varying spatial-frequency relationship in ERP. The phase synchronization for inattentional visual stimulus was not observed.

목적: 정상안에서 Fourier domain OCT (FD OCT)를 이용하여 황반두께 및 부피를 측정하여 Stratus OCT와 비교하였으며 황반질환안과 차이가 있는지 알아보고자한다. 대상과 방법: 23명 35안의 정상안과 24명 26안의 황반질환안 환자를 같은 시간대에 FD OCT와 Stratus OCT를 이용하여 황반두께와 총 황반부피를 구하여 서로 비교하였다. 결과: 전체 대상안의 중심와 망막두께는 FD OCT에서 251.49±79.45 μm, Stratus OCT에서 210.26±60.57 μm이었으며, 총황반부피는 각각 7.72±1.06 mm³, 7.04±0.96 mm³이었다. 9개의 ETDRS subfield 모든 영역에서 통계적으로 유의하게 FD OCT에서 Stratus OCT보다 더 두껍게 나타났다. 정상안 군과 황반질환안 군으로 나누어 비교했을 때에도 FD OCT가 통계적으로 유의하게 두껍게 나타났다. 결론: 정상안 군과 황반질환안 군 모두에서 망막두께 측정값이 FD OCT가 Stratus OCT보다 더 두꺼웠고 황반부피가 높았다. 이는 FD OCT는 망막색소상피 상부를 기준하여 시세포 외분절을 포함한 망막두께를 측정하기 때문이다. 따라서 FD OCT결과를 해석하거나 Stratus OCT 결과와 비교할 때는 이 점을 고려해야 한다.

Purpose: To define and measure macular thickness and volume using Fourier domain OCT (FD OCT) and compare the values with Stratus OCT in normal eyes and eyes with macular disease. Methods: On the same day, macular thicknesses of the ETDRS 9 subfield and total macular volumes were measured in 35 eyes of 23 normal subjects and 19 diseased eyes of 24 patients with FD OCT and Stratus OCT. The macular cube scan protocol for FD OCT and the fast macular thickness map protocol for Stratus OCT were used to measure macular thicknesses. Results: Foveal thickness of the central subfield in FD OCT (251.49±79.45 μm) was thicker than the value of Stratus OCT (210.26 ±60.57 μm) (p<0.001) in all eyes. Total macular volume was 7.72±1.06 mm³ and 7.04±0.96 mm³ for FD OCT and Stratus OCT, respectively (p<0.001). Retina thickness of the ETDRS 9 subfields in FD OCT was thicker than the value obtained using Stratus OCT. In addition, foveal thickness differences were statistically significant in both the normal and diseased eye groups. Conclusions: Macular thickness and total macular volume as measured by the FD OCT were larger than the values obtained using the Stratus OCT in both the normal and the diseased eye groups. The measuring algorithm of FD OCT defines the top of RPE as the outer retinal boundary, but Stratus OCT defines the outer retinal boundary as the IS/OS junction of the photoreceptor. Therefore, macular thicknesses of FD OCT are thicker than those of Stratus OCT. This difference should be considered when comparing the results of FD OCT with those of Stratus OCT.

목적: 시간영역 빛간섭단층촬영기(stratus-optical coherence tomography)와 스펙트럼영역 빛간섭단층촬영기(3D-OCT)로 측정한 망막신경섬유층의 두께를 비교하였다. 대상과 방법: 정상 69안과 녹내장 92안을 대상으로 같은 날 Stratus-OCT의 fast RNFL scan과 3D-OCT의 optic disc cube scan으로유두주위 망막신경섬유층 두께를 구하였고, 두 측정치의 연관성을 알아보기 위해 상관분석과 Bland-Altman plot을 이용하였다. 결과: 전 대상에서 평균, 상사분면, 하사분면 망막신경섬유층 두께는 Stratus-OCT가 3D-OCT보다 두꺼웠고, 반면에 이측사분면, 비측사분면에서는 3D가 Stratus보다 두꺼웠다. 두 기기 간에 절대치는 차이가 있었으나 상관계수는 높았다(r=0.678-0.905). Bland-Altman plot에서 상대적으로 두꺼운 망막신경섬유층 두께에서는 Stratus-OCT가 3D-OCT보다 두껍게 측정되었고, 얇은 두께에서는 3D가Stratus보다 두껍게 측정되었다. 결론: 두 기기의 측정치를 비교할 때 망막신경섬유층 두께에 따라 차이가 있음을 고려하여야 한다.

Purpose: To compare retinal nerve fiber layer (RNFL) thickness measured by time domain (Stratus) and spectral domain (3D) optical coherence tomography (OCT). Methods: Sixty-nine normal subjects and 92 glaucoma patients were included in the present study. Peripapillary RNFL thickness was measured with Stratus fast RNFL scan and 3D optic disc cube scan on the same day. The relationship between RNFL thickness measurements of the two OCTs were evaluated using a Pearson’s correlation analysis. A Bland-Altman plot was used for the comparison of Stratus-OCT and 3D-OCT. Results: In all subjects, average, superior, and inferior quadrant RNFL thicknesses measured by Stratus-OCT were thicker than those measured by 3D-OCT. In contrast, temporal and nasal quadrant RNFL thicknesses measured by 3D-OCT were thicker than those measured by Stratus-OCT. Although there were absolute value differences in RNFL thicknesses,high correlation was observed between Stratus-OCT and 3D-OCT (average: r = 0.897, temporal quadrant: r = 0.728, superior quadrant: r = 0.811, nasal quadrant: r = 0.678, and inferior quadrant: r = 0.905). Bland-Altman plots showed that Stratus-OCT values were greater than 3D-OCT values with relatively high RNFL thickness and the opposite with low RNFL thickness. Conclusions: For thicker RNFL, Stratus-OCT measurements tend to be greater than 3D-OCT, while for thinner RNFL,3D-OCT measurements tend to be greater than Stratus-OCT. This difference must be taken into account if comparing measurements made with a Stratus-OCT to the measurements of a 3D-OCT.

목적: 시간 및 스펙트럼영역 빛간섭단층촬영기(TD and SD OCT)를 이용하여 정상안에서 유리체황반경계면을 비교하였다. 대상과 방법: 정상 69안(52.7 ± 15.4세)에서 두 OCT로 관찰한 유리체황반경계면을 vitreomacular separation (VMS)이 전혀 없는 군(no VMS), 불완전한 군(incomplete VMS), 구분할 수 없는 군(unknown)으로 분류하였다. 결과: TD OCT에서 no VMS, incomplete VMS, unknown 각각 2안(2.9%), 2안(2.9%), 65안(94.2%)이었고, SD OCT에서 각각 31안(45.0%), 13안(18.8%), 25안(36.2%)이었다. SD OCT에서 no VMS로 분류된 31안 중 29안(93.5%)에서 TD OCT로 unknown군이었다(p˂0.0001). SD OCT에서 incomplete VMS인 13안 중에서 2안(15.4%)에서만 TD OCT로 같은 군이었고, 나머지에서는 unknown군이었다(p˂0.0001). SD OCT에서 unknown 모두에서 TD OCT로 같은 군이었다. 결론: 유리체황반유착이 존재하는 경우에는 SD OCT가 TD OCT보다 유리체황반경계면 평가에 유용하다.

Purpose: To compare the efficacy of time domain (TD) and spectral domain (SD) optical coherence tomography (OCT) in determining vitreomacular interface (VMI). Methods: VMIs were evaluated with TD and SD OCT images crossing the fovea horizontally in 69 eyes (mean age 52.7 ±15.4 years) and were classified as follows: (1) no vitreomacular separation (VMS), (2) incomplete VMS, and (3) unknown. Results: In TD OCT, no VMS was observed in 2 eyes (2.9%), incomplete VMS in 2 eyes (2.9%), and unknown in 65 eyes (94.2%). In SD OCT, no VMS was observed in 31 eyes (45.0%), incomplete VMS in 13 eyes (18.8%), and unknown in 25eyes (36.2%). In 31 eyes with no VMS on SD OCT, 29 eyes (93.5%) presented unknown on TD OCT (p<0.0001). In 13eyes with incomplete VMS on SD OCT, 2 eyes (15.4%) showed incomplete VMS and 11 eyes (84.6%) showed unknown on TD OCT (p<0.0001). TD OCT was also non-informative in all 25 eyes with unknown on SD OCT. Conclusions: SD OCT allows better visualization of VMI than TD OCT, especially in patients with no VMS.

이 논문에서는 SAR 위성영상을 사용하여 도시 국소지역에 대한 시계열 변화탐지를 위한 Statistically Homogeneous Pixel (SHP) 및 긴밀도(coherence) 정보 기반의 방법을 제안하였다. 제안된 시계열 변화탐지 프레임워크(framework)를 다목적실용위성(KOMPSAT) 5호 Synthetic Aperture Radar (SAR) 시계열 데이터에 적용하여 항만 지역의 컨테이너 적치장에 대한 시계열 변화탐지 실험을 수행하였다. 향후 보다 많은 영상을 대상으로 기술 검증이 이루어진다면 국내 다목적실용위성 SAR 영상을 활용한 도시지역의 관심지역에 대한 시계열 변화탐지 알고리즘이 더 일반화되고 신뢰도를 높일 수 있을 것이다.

In this paper, we proposed a method based on statistically homogeneous pixel (SHP) and coherence information for time series change detection of urban areas using synthetic aperture radar (SAR) images. The proposed framework was applied to KOMPSAT-5 SAR time series data to conduct time series change detection experiments on container yards in port areas. If the algorithm is verified with more SAR images in the future, the algorithm for detecting time series changes in areas of interest using domestic KOMPSAT SAR satellite images will become more generalized and reliable.

본 논문은 서봉총의 축조시기와 관련하여, 銀盒에 새겨진 延壽라는 연호와 辛卯라는 年 干支에 주목하고자 한다. 연수라는 연호는 중국, 일본에서 사용된 예가 없다. 신묘년에 관해서는, 1) 391년(新羅 奈勿尼師今 36年, 高句麗 故國壤王 8年). 2) 451년 (新羅 訥祗痲立干 35年, 高句麗 長壽王 39年). 3) 511년(新羅 智證王 12年, 高句麗 文咨王 20年)으로 보는 견해가 있다. 그런데 1)의 391년은 고구려 고국양왕 8년이었다. 이 때, 고구려는 국가적인 법회를 열었고, 國社(社稷)를 세우고, 宗廟를 수리했다. 이로 보아, 서봉총에 매납된 은합은 고구려의 법회 또는 제사와 관련된 용도로 쓰였을 것이다. 따라서 연수라는 연호는 신묘라는 간지와 연관해 보면, 고구려 고국양왕의 것으로 생각된다. 이 때 고구려는 신라에 대해, 상위국으로 있었다. 이 점은 내물왕대에 신라가 고구려에게 인질을 보낸 것에서 알 수 있다. 또한 내물왕의 뒤를 이은 실성왕의 즉위에는 고구려세력이 개입되어 있었다. 이러한 시대적 배경으로, 신라 내물왕과 실성왕 무렵에 고구려의 연호인 연수가 새겨진 은합이 서봉총에 매납 되었다고 보인다. 그리고 은합에 새겨진 신묘 년이 2) 451년 (신라 눌지마립간 35년, 고구려 장수왕 39년)과 3) 511년(신라 지증왕 12년, 고구려 문자왕 20년)이라는 설은 고구려와 신라의 관계로 보아 합리적이지 않다. 왜냐하면 이 때, 고구려와 신라는 적대적인 관계로 변화되어 있었기 때문이다. 이 시기에, 신라는 왕릉급 무덤인 서봉총에 고구려의 연호가 새겨진 은합을 귀중한 유물로 여겨 매납하지는 않았을 것이다.