• JSTS:Journal of Semiconductor Technology and Science
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• 제1권4호
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• pp.239-247
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• 2001

The Fluorescence-Activated Cell Sorter (FACS) is a well-established instrument used for identifying, enumerating, classifying and sorting cells by their physical and optical characteristics. For a miniaturized FACS device, a disposable plastic microchip has been developed which has a hydrodynamic focusing chamber using soft lithography. As the characteristics of the spatially confined sample stream have an effect on sample throughput, detection efficiency, and the accuracy of cell sorting, systematic fluid dynamic studies are required. Flow visualization is conducted with a laser scanning confocal microscopy (LSCM), and three-dimensional flow structure of the focused sample stream is reconstructed from 2D slices acquired at $1\mutextrm{m}$ intervals in depth. It was observed that the flow structure in the focusing chamber is skewed by unsymmetrical velocity profile arising from trapezoidal cross section of the microchannel. For a quantitative analysis of a microscopic flow structure, Confocal Micro-PIV system has been developed to evaluate the accelerated flow field in the focusing chamber. This study proposes a method which defines the depth of the measurement volume using a detection pinhole. The trajectories of red blood cells (RBCs) and their interactions with surrounding flow field in the squeezed sample stream are evaluated to find optimal shape of the focusing chamber and fluid manipulation scheme for stable cell transporting, efficient detection, and sorting

• 한국생활과학회지
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• 제19권3호
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• pp.555-563
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• 2010

With recent advances in 3D scanning technology, three-dimensional (3D) patternmaking is becoming a powerful way to develop garments pattern. This technology is now applicable to the made to measure (MTM) system of both ordinary and tightly fitting garments. Although the pattern of fitted clothing has been developed using 3D human data, it is still interesting to develop cycling pants by considering while-cycling body posture and fabric elasticity. This study adopted the Garland's triangle simplification method in order to simplify data without distorting the original 3D scan. Next, the Runge-Kutta method (2C-AN program) was used to develop a 2D pattern from the triangular pixels in the 3D scanned data. The 3D scanned data of four male, university students aged from 21 to 25, was obtained using Whole body scanner (Model WB4, Cyberware, Inc., USA). Results showed the average error of measurement was $4.58cm^2$ (0.19%) for area and 0~0.61cm for the length between the 3D body scanned data and the 2D developed pattern data. This is an acceptable range of error for garment manufacture. Additionally, the 2D pattern developed, based on the 3D body scanned data, did not need ease for comfort or ease of movement when cycling. This study thus provides insights into how garment patterns may be developed for ergonomic comfort in certain special environments.

• 한국터널지하공간학회 논문집
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• 제14권4호
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• pp.437-451
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• 2012

최근 3차원 레이저 스캐너는 토목 분야의 적용에 관한 다수의 연구가 수행되고 있으며, 연구 분야 역시 터널 및 교량, 토공량 산정, 시공검측, 암반절리 측정 등 여러 분야에서 이루어지고 있다. 그 중 터널 시공 시 여굴량 및 미굴량을 산정함에 있어 3차원 레이저 스캐너를 활용하는 연구가 점차적으로 이루어지고 있으며, 지금까지의 연구는 스캔 데이터와 2차원 CAD 도면과의 비교를 통해 여굴량 및 미굴량을 산정하는 방식으로 이루어 졌다. 그러나 터널이 비교적 단순한 형상의 구조물이라 하더라도 3차원 형상의 구조물로 정확한 여굴량 및 미굴량을 산정하기 위해서는 3차원적인 비교가 필요하다. 본 연구에서는 3차원 레이저 스캐너로 획득한 스캔 데이터와 3차원 설계 모델링인 BIM을 활용하여 시공시 발생하는 여굴량 및 미굴량을 산정하는 시공오차 평가 프로그램을 개발하였으며, 이를 위한 효율적인 스캔 데이터의 처리 프로세스를 제안하였다. 또한 실제 현장에 3차원 레이저 스캐너를 적용하여 시공오차를 산정하였으며, 프로그램의 성능을 검증하였다.

• 한국측량학회지
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• 제39권5호
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• pp.343-349
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• 2021

In The process from design to construction in the existing construction work was less efficient due to the contradictory approach of identifying the 3D state in the plan view and the repeated generation of surveys, floor plans, drawings. Accurate 3D design data is essential for smart construction. However, most of the existing related studies have focused on explaining the development method and main functions of equipment or improving the productivity of smart construction. Therefore, in this study, the utility of 3D design model generation for smart construction and construction survey using 3D laser scanner was evaluated. Plane and vertical road alignment were created using the specifications of the road. The generated road alignment was created as a three-dimensional corridor design using cross-sections at intervals of 20m. In addition, it was possible to create a DTM (Digital Terrain Model) using a digital map and effectively create a 3D design model for the study area through overlapping. Construction survey using a 3D laser scanner showed accuracy within 10cm as a result of the accuracy evaluation. These results proved that construction surveying using a 3D laser scanner is possible because it satisfies the acceptable accuracy of the relevant regulations modeling of target areas using 3D design and construction survey using 3D laser scanner can be a way to address shortcomings of existing GNSS (Global Navigation Satellite System) methods. And accurate 3D data will be used as essential data as basic data for smart construction.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.24.1-24.7
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• 2020

Background: In daily practice, three-dimensional patient-specific jawbone models (3D models) are a useful tool in surgical planning and simulation, resident training, patient education, and communication between the physicians in charge. The progressive improvements of the hardware and software have made it easy to obtain 3D models. Recently, in the field of oral and maxillofacial surgery, there are many reports on the benefits of 3D models. We introduced a desktop 3D printer in our department, and after a prolonged struggle, we successfully constructed an environment for the "in-house" fabrication of the previously outsourced 3D models that were initially outsourced. Through various efforts, it is now possible to supply inexpensive 3D models stably, and thus ensure safety and precision in surgeries. We report the cases in which inexpensive 3D models were used for orthodontic surgical simulation and discuss the surgical outcomes. Review: We explained the specific CT scanning considerations for 3D printing, 3D printing failures, and how to deal with them. We also used 3D models fabricated in our system to determine the contribution to the surgery. Based on the surgical outcomes of the two operators, we compared the operating time and the amount of bleeding for 25 patients who underwent surgery using a 3D model in preoperative simulations and 20 patients without using a 3D model. There was a statistically significant difference in the operating time between the two groups. Conclusions: In this article, we present, with surgical examples, our in-house practice of 3D simulation at low costs, the reality of 3D model fabrication, problems to be resolved, and some future prospects.

• 센서학회지
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• 제28권3호
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• pp.157-163
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• 2019

The LiDAR sensor, which is widely regarded as one of the most important sensors, has recently undergone active commercialization owing to the significant growth in the production of ADAS and autonomous vehicle components. The LiDAR sensor technology involves radiating a laser beam at a particular angle and acquiring a three-dimensional image by measuring the lapsed time of the laser beam that has returned after being reflected. The LiDAR sensor has been incorporated and utilized in various devices such as drones and robots. This study focuses on object detection and recognition by employing sensor fusion. Object detection and recognition can be executed as a single function by incorporating sensors capable of recognition, such as image sensors, optical sensors, and propagation sensors. However, a single sensor has limitations with respect to object detection and recognition, and such limitations can be overcome by employing multiple sensors. In this paper, the performance of an eight-channel scanning LiDAR was evaluated and an object detection algorithm based on it was implemented. Furthermore, object detection characteristics during daytime and nighttime in a real road environment were verified. Obtained experimental results corroborate that an excellent detection performance of 92.87% can be achieved.

• 대한치과보철학회지
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• 제42권3호
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• pp.307-326
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• 2004

Statement of problem. The long-term success of implants is the development of a stable direct connection between bone and implant surface, which must be structural and functional. To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. Among them, altering the surface properties can modify cellular responses such as cell adhesion, cell motility and bone deposition. Purpose. This study was to evaluate the cellular behaviors on the surface-modified titanium by morphological observation, cellular proliferation and differentiation. Material and methods. Specimens were divided into five groups, depending on their surface treatment: electropolishing(EP) anoclizing(AN), machining(MA), blasting with hydroxyapatite particle(RBM) and electrical discharge machining(EDM). Physicochemical properties and microstructures of the specimens were examined and the responses of osteoblast-like cells were investigated. The microtopography of specimens was observed by scanning electron microscopy(SEM). Surface roughness was measured by a three-dimensional roughness measuring system. The microstructure was analyzed by X-ray diffractometer(XRD) and scanning auger electron microscopy(AES). To evaluate cellular responses to modified titanium surfaces, osteoblasts isolated from neonatal rat were cultured. The cellular morphology and total protein amounts of osteoblast-like cell were taken as the marker for cellular proliferation, while the expression of alkaline phosphatase was used as the early differentiation marker for osteoblast. In addition, the type I collagen production was determined to be a reliable indicator of bone matrix synthesis. Results. 1. Each prepared specimen showed specific microtopography at SEM examination. The RBM group had a rough and irregular pattern with reticulated appearance. The EDM-treated surface had evident cracks and was heterogeneous consisting of broad sheet or plate with smooth edges and clusters of small grains, deep pores or craters. 2. Surface roughness values were, from the lowest to the highest, electropolished group, anodized group, machined group, RBM group and EDM group. 3. All groups showed amorphous structures. Especially anodized group was found to have increased surface oxide thickness and EDM group had titaniumcarbide(TiC) structure. 4. Cells on electropolished, anodized and machined surfaces developed flattened cell shape and cells on RBM appeared spherical and EDM showed both. After 14 days, the cells cultured from all groups were formed to be confluent and exhibited multilayer proliferation, often overlapped or stratified. 5. Total protein amounts were formed to be quite similar among all the group at 48 hours. At 14 days, the electropolished group and the anodized group induced more total protein amount than the RBM group(P<.05). 6. There was no significant difference among five groups for alkaline phosphatase(ALP) activity at 48 hours. The AN group showed significantly higher ALP activity than any other groups at 14 days(P<.05). 7. All the groups showed similar collagen synthesis except the EDM group. The amount of collagen on the electropolished and anodized surfaces were higher than that on the EDM surface(P<.05).

• 지구물리와물리탐사
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• 제9권4호
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• pp.279-290
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• 2006

이 연구에서는 다양한 시추공 레이다 탐사법 중, 지하 갱도의 탐지에 사용이 가능한 (1) 시추공 레이다 반사법 탐사, (2) 방향성 안테나를 이용한 반사법 탐사, (3) 크로스홀 스캐닝(crosshole scanning), (4) 레이다 토모그래피 등의 4 종류 시추공 레이다 탐사법의 터널 탐지에 대한 적용성과 한계성을 탐사 사례 분석을 통해 고찰하였다. 시추공 레이다 반사법 탐사의 터널로부터 회절 양상은 완벽한 포물선 형태보다는 상부 포물선만 명확히 나타난 형태가 많았고 그 회절 이벤트는 정점을 기준으로 아래, 위 10 m 이상에 이르는 트레이스 까지 나타났다. 또한 안테나의 길이에 비해 시추공의 공경이 커지면 링잉 현상이 많이 발생함을 확인하였다. 송 수신 거리(offset)에 따라 신호의 양상이 많이 달라지며 현장여건에 따라 송 수신 거리를 조절하면 더 좋은 분해능의 자료를 획득할 수 있을 것이다. 방향성 안테나 시스템은 한 시추공만을 이용하여 터널의 3차원적인 위치를 정확히 판별할 수 있는 장점이 있으나 장비의 가격이 고가이며, 현장 작업의 난이도가 매우 높고, 시간이 많이 걸리는 단점이 있다. 크로스홀 스캐닝는 터널의 유무에 대한 좋은 지표가 될 수 있음을 알 수 있었으며 시추공 레이다 반사법 탐사와 같이 사용된다면 높은 신뢰도의 결과를 낼 수 있을 것이다. 레이다 토모그래피는 터널을 영상화함과 동시에 주변의 지반 물성을 얻게 되어 지하구조 파악에 효과적이라고 할 수 있다. 위의 결과를 토대로 경제적이고 효과적인 터널 탐지 방법을 제안하면, 먼저 시추공 레이다 반사법 탐사를 수행하여 이상 징후를 탐지 한 후, 주변의 시추공 상황에 따라 크로스홀 스캐닝이나 방향탐지 안테나를 도입하여 확인하는 것이다.

• 공업화학
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• 제27권6호
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• pp.653-658
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• 2016

본 연구에서는 1차원의 $MnO_2$ nanowire를 $KMnO_4$와 $MnSO_4$ 전구체 혼합물의 수열합성법(hydrothermal method)을 사용하여 제조할 수 있는 합성법을 개발하였다. 제조된 $MnO_2$ nanowire는 전기화학 반응 동안 전자와 이온전달을 용이하게 할 수 있는 넓은 비표면적과 기공구조를 나타내었다. MnO2 nanowire의 미세구조 및 화학구조를 주사형 전자현미경(SEM), 투과전자현미경(TEM), 광전자분석기(XPS), X-ray 회절분석법(XRD), 비표면적분석장비(BET)를 사용하여 분석하였다. 본 $MnO_2$ nanowire 전극의 전기화학적 특성은 순환전압전류법(cyclic voltammetry)과 정전류 충전-방전법(galvanostatic charge-discharge)을 사용하여 3상 전극 시스템(three-electrode system)에서 분석하였다. $MnO_2$ nanowire 전극은 높은 비정전용량(129 F/g), 고속 충방전(61% retention), 반 영구적인 수명특성(100%)을 나타내었다.

• 한국정보통신학회논문지
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• 제19권11호
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• pp.2689-2696
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• 2015

방사선 진단에 사용되는 방사성동위원소 중 사이클로트론을 이용해 생산되는 방사성동위원소는 사이클로트론에서 인출된 양성자 빔이 타겟에 조사될 때 빔의 크기와 모양, 조사되는 위치에서 빔 균일 정도에 따라 생산 수율에 영향을 받는다. 이에 본 논문에서는 사이클로트론 빔 라인에서 빔의 단면을 측정할 수 있는 BPM(Beam Profile Monitor)장치를 개발하였다. LabView로 BPM장치를 원격 제어할 수 있도록 구성하였으며 BPM 프로그램을 이용하여 X축과 Y축으로 텅스텐 와이어를 스캔하면서 얻은 빔의 수치 정보를 2차원 그래프와 3차원 빔 분포 그래프로 표시하여 해석을 쉽게 모니터링 할 수 있도록 하였다. 빔을 측정하는 데 걸리는 시간은 스텝 모터 구동 속도가 2000pps일 때 37초가 걸린다는 것을 확인 할 수 있었다. 측정된 빔 분포정보를 기반으로 빔 재조정을 통해 빔 분포를 최적화함으로써 방사성동위원소 생산 수율을 극대화 시킬 수 있고 공급 안정화에도 기여하리라 본다.