• 분석과학
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• 제23권6호
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• pp.537-543
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• 2010

도파민은 카테콜아민류의 중요한 신경전달물질로서 부족하면 파킨스병과 정신분열증 등을 야기할 수 있다. 그러므로 조작이 비교적 간단하면서 감도가 우수한 분석법의 개발이 필요하다. 이에, 도파민에 대한 경쟁적인 효소면역분석법이 연구되었다. 경쟁적인 면역분석법의 분석감도는 일반적으로 두가지 요소에 의해 조절된다. 하나는 경쟁자의 특성과 농도이며, 다른 하나는 결합체, 즉 항체의 그것이다. 따라서, 경쟁자인 BSA-DA과 결합체인 항체-avidin 접합체의 최적화가 수행되었다. 두 접합체는 SATA와 SMCC를 이용한 dual heterobifunctional coupling법에 의해 합성되었으며, 최적화 과정을 통해 BSA-DA 접합체의 농도는 $6.66\;{\mu}g/mL$, 항체-avidin 접합체의 농도 $4.17{\times}10^{-10}\;M$로 결정되었다. 도파민에 대한 doseresponse curve와 calibration curve의 결과로써 도파민에 대한 검출 한계는 $2.3{\times}10^{-2}\;{\mu}g/mL$ 이고 검출 영역은 $1.0{\times}10^{-3}\;M\sim1.0{\times}10^{-7}\;M$ 이다. 직선성을 갖는 검출영역에서의 검정선을 얻은 결과 [Absorbance = -0.1098 log[DA]+0.0353 ($R^2$ = 0.9956)] 우수한 직선관계를 얻었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.294-297
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• 2007

Steam and advection fogs are frequently observed in the Yellow Sea located between Korea and China during the periods of March-April and June-July respectively. This study uses the remote sensing (RS) data for monitoring sea fog. Meteorological data obtained from the Ieodo Ocean Research Station provided an informative synopsis for the occurrence of steam and advection fogs through a ground truth. The RS data used in this study was GOES-9, MTSAT-1R images and QuikSCAT wind data. A dual channel difference (DCD) approach using IR and near-IR channel of GOES-9 and MTSAT-1R satellites was applied to estimate the extension of the sea fog. For the days examined, it was found that not only the DCD but also the texture-related measurement and the weak wind condition are required to separate the sea fog from the low cloud. The QuikSCAT wind is used to provide a weak wind area less than threshold under stable condition of the surface wind around a fog event. The Laplacian computation for a measurement of the homogeneity was designed. A new combined method of DCD, QuikSCAT wind speed and Laplacian was applied in the twelve cases with GOES-9 and MTSAT-1R. The threshold values for DCD, QuikSCAT wind speed and Laplacian are -2.0 K, 8 m $s^{-1}$ and 0.1, respectively. The validation methods such as Heidke skill score, probability of detection, probability of false detection, true skill score and odds ratio show that the new combined method improves the detection of sea fog rather than DCD method.

• 한국전자파학회논문지
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• 제17권3호
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• pp.272-279
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• 2006

본 논문에서는 W-CDMA(Wide band Code Division Multiple Access) 시스템에서 채널 측정 및 프레임 동기 확인에 사용되는 파일럿 비트 패턴의 프레임 동기 단어(frame synchronization words) 성능을 분석한다. 또한 W-CDMA 시스템에서는 두 개의 수신 단말기를 갖지 않고도, 다른 주파수의 측정을 하기 위해 압축 모드(compressed mode)를 사용한다. 제안된 프레임 동기용 이원 부호의 우선 쌍 간의 보완 매핑(complementary mapping) 관계를 이용하면, 압축 모드에서도 프레임 동기 특성을 유지함을 컴퓨터 시뮬레이션을 통하여 확인한다. 검출 확률과 오 경보 확률을 갖는 수신기 동작 특성(ROC: Reciever Operating Characteristic) 곡선은 LLRT(Log Likely-hood Ratio Test), GLRT(Generalied Likeiyhood Ratio Test), 연판정(soft correlation test), 경 판정(hard correlarion test)과 같은 다양한 검출법(detection metrics)을 이용하여 레일레이 페이딩 채널에서 제안된 프레임 동기 단어의 성능 분석에 사용된다. 이 논문의 파일럿 비트 패턴의 성능에 대한 연구 결과는 3세대 W-CDMA 시스템에서 프레임 동기의 설계 및 구현에 유용한 참고 자료가 될 수 있을 것이다.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2007년도 학술대회 3부
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• pp.306-317
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• 2007

We present an interactive and accurate collision detection algorithm for deformable, polygonal objects based on the streaming computational model. Our algorithm can detect all possible pairwise primitive-level intersections between two severely deforming models at highly interactive rates. In our streaming computational model, we consider a set of axis aligned bounding boxes (AABBs) that bound each of the given deformable objects as an input stream and perform massively-parallel pairwise, overlapping tests onto the incoming streams. As a result, we are able to prevent performance stalls in the streaming pipeline that can be caused by expensive indexing mechanism required by bounding volume hierarchy-based streaming algorithms. At run-time, as the underlying models deform over time, we employ a novel, streaming algorithm to update the geometric changes in the AABB streams. Moreover, in order to get only the computed result (i.e., collision results between AABBs) without reading back the entire output streams, we propose a streaming en/decoding strategy that can be performed in a hierarchical fashion. After determining overlapped AABBs, we perform a primitive-level (e.g., triangle) intersection checking on a serial computational model such as CPUs. We implemented the entire pipeline of our algorithm using off-the-shelf graphics processors (GPUs), such as nVIDIA GeForce 7800 GTX, for streaming computations, and Intel Dual Core 3.4G processors for serial computations. We benchmarked our algorithm with different models of varying complexities, ranging from 15K up to 50K triangles, under various deformation motions, and the timings were obtained as 30~100 FPS depending on the complexity of models and their relative configurations. Finally, we made comparisons with a well-known GPU-based collision detection algorithm, CULLIDE [4] and observed about three times performance improvement over the earlier approach. We also made comparisons with a SW-based AABB culling algorithm [2] and observed about two times improvement.

• Smart Structures and Systems
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• 제6권5_6호
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• pp.731-748
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• 2010

Impact detection and health monitoring are very important tasks for civil infrastructures, such as bridges. Piezoceramic based transducers are widely researched for these tasks due to the piezoceramic material's inherent advantages of dual sensing and actuation ability, which enables the active sensing method for structural health monitoring with a network of piezoceramic transducers. Wireless sensor networks, which are easy for deployment, have great potential in health monitoring systems for large civil infrastructures to identify early-age damages. However, most commercial wireless sensor networks are general purpose and may not be optimized for a network of piezoceramic based transducers. Wireless networks of piezoceramic transducers for active sensing have special requirements, such as relatively high sampling rate (at a few-thousand Hz), incorporation of an amplifier for the piezoceramic element for actuation, and low energy consumption for actuation. In this paper, a wireless network is specially designed for piezoceramic transducers to implement impact detection and active sensing for structural health monitoring. A power efficient embedded system is designed to form the wireless sensor network that is capable of high sampling rate. A 32 bit RISC wireless microcontroller is chosen as the main processor. Detailed design of the hardware system and software system of the wireless sensor network is presented in this paper. To verify the functionality of the wireless sensor network, it is deployed on a two-story concrete frame with embedded piezoceramic transducers, and the active sensing property of piezoceramic material is used to detect the damage in the structure. Experimental results show that the wireless sensor network can effectively implement active sensing and impact detection with high sampling rate while maintaining low power consumption by performing offline data processing and minimizing wireless communication.

• 대한원격탐사학회지
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• 제38권5_2호
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• pp.737-746
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• 2022

전천후 자료 취득이 가능한 SAR 영상을 기반으로 한 선박 탐지와 인공지능 기반 탐지 알고리즘과 함께 사용하는 것은 안정적인 선박 모니터링에 효과적이다. 기존의 SAR 영상에서는 인공지능 기반 선박 탐지 알고리즘에 진폭 영상만을 주로 사용하였으며, 물체의 산란 특성을 구분할 수 있는 다중 편파 SAR 영상의 편파 지표는 사용되지 않았다. 이에, 본 연구에서는 이중 편파 Sentinel-1 SAR 영상으로부터 고유값 분해를 통해 취득한 4개의 편파 지표인 H, p₁, DoP, DPRVI와 방사 보정을 통해 취득한 2개 편파의 산란계수인 γ₀, _VV, γ₀, _VH를 이용하여 총 6개의 밴드를 가진 SAR 영상 52장의 데이터베이스를 구축하고, 이와 상응하는 시간에 취득한 선박의 실시간 위치 및 속도 정보인 AIS 자료를 사용하여 학습자료를 추출하였다. 구축된 밴드 조합에 대해 선박탐지 정확도를 평가한 결과, 이중 편파 지표를 진폭과 함께 사용한 경우 진폭 값만을 사용했을 때에 비해 개선된 탐지 정확도를 보였다.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.624-629
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• 2018

본 논문은 NDIR(Non Dispersive Infra Red) 방식을 적용하여 $CO_2$ 및 $CH_4$의 두 가지 가스를 하나의 휴대용 장치에서 측정이 가능하도록 제작된 복합 가스 측정 장치에 대한 연구이다. 측정 장치의 구성은 적외선램프에서 적외선이 방출되면 방출된 파장이 광학창을 거치면서 흡수로 인하여 빛이 줄어들게 되고 이 감소량(흡수도)을 검출기에서 검출하고 이를 전기적 신호로 변환 증폭하여(3.5V~6V) 정확한 측정이 가능함을 보여준다. 기존의 Single Sensor 방식은 적외선에서 특수파장을 흡수하여 상대 측정량을 검출하는 방식으로 가스의 경우 $4.26{\mu}m$파장의 빛만을 검출하여 측정하는 방식으로 센서의 값을 보정할 수 있는 기준센서가 없어 오차가 발생하는 문제가 발생하였다. 본 연구에 적용된 Dual Sensor 방식은 다른 가스의 영향을 받지 않는 $3.91{\mu}m$의 기준치와 가스의 $4.26{\mu}m$의 두 파장을 검출하여 비교측정 함으로써 오차가 적어 신뢰도가 높은 방식으로, 휴대형으로 소형화하여 저 전력화가 가능하며, $CO_2$ 및 $CH_4$의 2가지 가스농도를 복합적으로 측정 할 수 있다는 특징이 있다. 측정 범위는 $CO_2$의 경우 0ppm~5,000ppm이고 $CH_4$의 경우는 0~5%의 부피 농도로 실내 공기량 1,000ppm을 측정 할 수 있도록 제작되어 휴대용이나 주택의 Home automation과 연동하여 소화연동이 가능함으로 화재예방에 매우 효과적일 것으로 확인하였다.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3784-3789
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• 2021

We report a simple technique for direct neutron spectroscopy using pure LaCl₃ crystals. Pure LaCl₃ crystals exhibit considerably better pulse shape discrimination (PSD) capabilities with relatively good energy resolution as compared with Ce-doped LaCl₃ crystals. Single crystals of pure and Ce-doped LaCl₃ were grown using an inhouse-developed Bridgman furnace. PSD capabilities of these crystals were investigated using ²⁴¹Am and ¹³⁷Cs sources. Fast neutron detection was tested using a²⁵²Cf source and three separate bands corresponding to electron, proton, and alpha were observed. The proton band induced by the ³⁵Cl(n,p)³⁵S reaction can be used for direct neutron spectroscopy because proton energy is proportional to incident neutron energy. Owing to good scintillation performance and excellent PSD capabilities, pure LaCl₃ is a promising candidate for space detectors and other applications that necessitate gamma/fast neutron discrimination capability.

• 한국산업융합학회 논문집
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• 제25권6_2호
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• pp.1003-1008
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• 2022

This paper proposes a method related to fault tolerance operation and characteristic analysis of asymmetric 6-phase permanent magnet synchronous motor. In general, motor drive systems with multi-phase structures can be continuously operated despite a reduction of power and speed by using a phase changeover or control techniques according to the failures. As a result, it is widely used in industrial fields such as aviation and defense, which require high efficiency and high reliability. In this paper, the second order ripple of the electrical fundamental freuqnecy occurs in the dq-axis currents of the synchronous coordinate system through mathematical analysis according to the switch open of the dual 3-phase inverter. Therefore, the fault tolerant operation method is presented by applying the fault detection method with a constant cycle for continuous operations. The effectiveness of the proposed fault tolerance operation method is verified through the several experiments.

• BMB Reports
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• 제57권3호
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• pp.155-160
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• 2024

Lung cancer carries one of the highest mortality rates among all cancers. It is often diagnosed at more advanced stages with limited treatment options compared to other malignancies. This study focuses on calnexin as a potential biomarker for diagnosis and treatment of lung cancer. Calnexin, a molecular chaperone integral to N-linked glycoprotein synthesis, has shown some associations with cancer. However, targeted therapeutic or diagnostic methods using calnexin have been proposed. Through 1D-LCMSMS, we identified calnexin as a biomarker for lung cancer and substantiated its expression in human lung cancer cell membranes using Western blotting, flow cytometry, and immunocytochemistry. Anti-calnexin antibodies exhibited complement-dependent cytotoxicity to lung cancer cell lines, resulting in a notable reduction in tumor growth in a subcutaneous xenograft model. Additionally, we verified the feasibility of labeling tumors through in vivo imaging using antibodies against calnexin. Furthermore, exosomal detection of calnexin suggested the potential utility of liquid biopsy for diagnostic purposes. In conclusion, this study establishes calnexin as a promising target for antibody-based lung cancer diagnosis and therapy, unlocking novel avenues for early detection and treatment.