• Journal of Korean Neurosurgical Society
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• 제61권3호
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• pp.363-375
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• 2018

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal age-adjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.

• Earthquakes and Structures
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• 제1권1호
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• pp.109-127
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• 2010

This work aims at introducing structural sensitivity analysis capabilities into existing commercial finite element software codes for the purpose of mapping retrofit strategies for a broad group of structures including heritage-type buildings. More specifically, the first stage sensitivity analysis is implemented for the standard deterministic environment, followed by stochastic structural sensitivity analysis defined for the probabilistic environment in a subsequent, second phase. It is believed that this new generation of software that will be released by the industrial partner will address the needs of a rapidly developing specialty within the engineering design profession, namely commercial retrofit and rehabilitation activities. In congested urban areas, these activities are carried out in reference to a certain percentage of the contemporary building stock that can no longer be demolished to give room for new construction because of economical, historical or cultural reasons. Furthermore, such analysis tools are becoming essential in reference to a new generation of national codes that spell out in detail how retrofit strategies ought to be implemented. More specifically, our work focuses on identifying the minimum-cost intervention on a given structure undergoing retrofit. Finally, an additional factor that arises in earthquake-prone regions across the world is the random nature of seismic activity that further complicates the task of determining the dynamic overstress that is being induced in the building stock and the additional demands placed on the supporting structural system.

• 천문학회보
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• 제38권2호
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• pp.84.1-84.1
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• 2013

We present a python-based data reduction pipeline for the Immersion GRating INfrared Spectrograph (IGRINS). IGRINS covers the complete H- and K-bands in a single exposure with a spectral resolving power of greater than 40,000. IGRINS is designed to be compatible with telescopes of diameters ranging from 2.7-m (the Harlan J. Smith telescope at McDonald Observatory) to 8-10m. Commissioning and initial operation will be on the 2.7-m telescope from late 2013. The pipeline package is a part of the IGRINS software and designed to be compatible with other package that maneuvers the spectrograph during the observation. This package provides high-quality spectra with minimal human intervention and the processes of order extraction, distortion correction, and wavelength calibration can be automatically carried out using the predefined functions (e.g. echellogram mapping and 2D transform). Since the IGRINS is a prototype of the Giant Magellan Telescope Near-Infrared Spectrometer (GMTNIRS), this pipeline will be extended to the GMTNIRS software.

• 대한원격탐사학회지
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• 제24권2호
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• pp.117-124
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• 2008

지형지물은 각각의 특징적 요인을 내포하고 있다. 이 특징적 요인들은, 공간해상도에 따라 정도의 차이가 있겠지만, 수집된 위성영상에도 반영된다. 이러한 요인들 중에서는 영상분류에 활용될 경우 영상 분류의 정확도를 높혀주고, 때로는 이것이 거의 물체인식의 수준까지 기여할 수 있는 것들이 있다. 이 연구에서는 텍스춰 및 지형지물의 배열에 있어서 특징적 현상을 보이는 비닐하우스를 대상으로 spatial auto-corelation 개념을 기반으로 자동적으로 이를 인지하는 방법을 개발하였다. 사용된 알고리즘은 디지타이징과 같은 사람의 직접적인 개입이 없이 자동화된 방법으로 비닐하우스의 특정한 패턴이 반복적으로 나타나는 것을 감지할 수 있도록 개발되었다. 패틴의 인식에 더하여 비닐하우스의 기하학적 모양을 고려하는 방법도 도입하였다. 그럼으로써 비닐하우스의 추출에 단순히 화소 단위의 분석이 아닌 보다 객체지향적인 방법으로 비닐하우스를 추출하도록 하였다. 개발된 방법을 제주지역의 IKONOS에 적용시켜 본 결과 연구대상지역내의 비닐하우스가 매우 정확하게 적출되었다.

• Korean Journal of Radiology
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• 제22권8호
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• pp.1352-1368
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• 2021

Objective: For an accurate dynamic contrast-enhanced (DCE) MRI analysis, exact baseline T1 mapping is critical. The purpose of this study was to compare the pharmacokinetic parameters of DCE MRI using synthetic MRI with those using fixed baseline T1 values. Materials and Methods: This retrospective study included 102 patients who underwent both DCE and synthetic brain MRI. Two methods were set for the baseline T1: one using the fixed value and the other using the T1 map from synthetic MRI. The volume transfer constant (K^trans), volume of the vascular plasma space (v_p), and the volume of the extravascular extracellular space (v_e) were compared between the two methods. The interclass correlation coefficients and the Bland-Altman method were used to assess the reliability. Results: In normal-appearing frontal white matter (WM), the mean values of K^trans, v_e, and v_p were significantly higher in the fixed value method than in the T1 map method. In the normal-appearing occipital WM, the mean values of v_e and v_p were significantly higher in the fixed value method. In the putamen and head of the caudate nucleus, the mean values of K^trans, v_e, and v_p were significantly lower in the fixed value method. In addition, the T1 map method showed comparable interobserver agreements with the fixed baseline T1 value method. Conclusion: The T1 map method using synthetic MRI may be useful for reflecting individual differences and reliable measurements in clinical applications of DCE MRI.

• 한국지역지리학회지
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• 제18권4호
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• pp.464-472
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• 2012

본 연구는 2010~2011년 한국에서 발생한 구제역이 시 공간에서 어떠한 군집 특징을 보이는가를 질병역학적 관점에서 지리정보시스템(GIS) 기반의 공간통계 방법으로 분석한 것으로 다음과 같은 주요 소견을 도출하였다. 첫째, 경기북부의 발생 사례에서는 가축 사육밀도가 높아 주변 농장으로 바이러스 전파가 용이한 환경에서는 구제역이 상대적으로 좁은 공간적 범위에서 시 공간 군집을 이루면서 전파되는 양상을 보였다. 둘째, 여주 이천 안성 등 경기도 남동부지역에서는 전체 구제역 발생 지점이 공간상으로는 밀집해 있지만 시간상으로는 분산되는 양상을 보였다. 셋째, 시간적 범위를 7일로 하였을 때 시 공간 군집의 평균 반경이 25km이고 최소 반경은 5.4km, 최대 반경은 74km로 분석되었다. 또한 구제역 발병 초기에는 군집의 반경이 작지만, 시간이 지남에 따라 군집의 반경이 커진다는 소견에 근거할 때 특정 지점에서 발생한 구제역에 대한 방역계획을 수립할 때 일차적으로 방역 범위에 대한 정확한 평가가 중요함을 시사한다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.34-37
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• 2006

When tsunami waves propagate across open ocean they are steered by Coriolis force and refraction due to gentle gradients in the bathymetry on scales longer than the wavelength. When the wave encounters steep gradients at the edges of continental shelves and at the coast, the wave becomes non-linear and conservation of momentum produces squirts of surface current at the head of submerged canyons and in coastal bays. HF coastal ocean radar is well-conditioned to observe the current bursts at the edge of the continental shelf and give a warning of 40 minutes to 2 hours when the shelf is 50-200km wide. The period of tsunami waves is invariant over changes in bathymetry and is in the range 2-30 minutes. Wavelengths for tsunamis (in 500-3000 m depth) are in the range 8.5 to over 200 km and on a shelf where the depth is about 50 m (as in the Great Barrier Reef) the wavelengths are in the range 2.5 - 30 km. It is shown that the phased array HF ocean surface radar being deployed in the Great Barrier Reef (GBR) and operating in a routine way for mapping surface currents, can resolve surface current squirts from tsunamis in the wave period range 20-30 minutes and in the wavelength range greater than about 6 km. There is a trade-off between resolution of surface current speed and time resolution. If the radar is actively managed with automatic intervention during a tsunami alert period (triggered from the global seismic network) then it is estimated that the time resolution of the GBR radar may be reduced to about 2 minutes, which corresponds to a capability to detect tsunamis at the shelf edge in the period range 5-30 minutes. It is estimated that the lower limit of squirt velocity detection at the shelf edge would correspond to a tsunami with water elevation of less than 5 cm in the open ocean. This means that the GBR HF radar is well-conditioned for use as a monitor of small and medium scale tsunamis, and has the potential to contribute to the understanding of tsunami genesis research.

• 한국전통조경학회지
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• 제37권1호
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• pp.1-11
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• 2019

본 연구는 도동서원 중정당 전면 담장의 보수를 위한 진단학적 보존 상태 분석을 하기 위해 수행되었다. 연구는 사진측량 및 도면화, 담장의 재료 및 보존 상태 조사, 담장의 보존 상태 분석 및 평가의 과정으로 진행되었으며, 연구결과는 다음과 같다. 첫째, 사진측량의 경우, 각 사진을 중첩되게 촬영하여, 사진들의 왜곡을 보정한 후 합성하였고, 이를 바탕으로 담장의 실측 도면을 마련하였다. 둘째, 담장의 재료 및 보존 상태의 경우, 담장은 와편담 형식이며, 머리 부분의 재료는 기와와 진흙, 석회이며, 몸통 부분의 재료는 진흙과 기와이다. 진흙은 자갈, 모래, 지푸라기를 섞어 사용되었다. 기초 부분에는 부정형의 자연석과 진흙이 사용되었다. 둘째, 담장에 나타나는 손상은 기초 부분의 침식 현상이 가장 두드러지게 나타나고 있으며, 몸통 부분에는 분해 현상이 일부 나타나고 있다. 머리 부분과 기초 부분에는 전체적으로 생물학적 파티나가 나타나고 있으며, 몸통 일부에는 지의류와 같은 식물이 집중 분포하고 있다. 머리 부분 전반에는 이물질이 쌓여 있고, 일부 기와는 깨지거나 유실되었다. 동쪽 담장의 일부 구간에는 깊은 균열이 집중적으로 위치하고 있다. 셋째, 담장의 보존 상태 분석 및 평가의 경우, 기초 부분의 침식 현상과 몸통 부분의 분해 현상은 방치할 경우 담장에 물리적 손상을 지속적으로 가할 가능성이 있어 즉각적인 조치가 필요하다고 판단된다. 생물학적 파티나와 식물의 분포는 담장에 큰 문제를 야기하고 있지 않는 것으로 보이나, 미학적인 문제를 고려해 감소시킬 필요가 있다. 깨지거나 유실된 기와는 교체가 필요하며, 동쪽 담장의 깊은 균열은 지반침하로 발생된 것으로 보이며 추가적인 손상을 막기 위해 담장 하부 지반 강화가 필요할 것으로 판단된다.