• KIEAE Journal
• /
• 제9권1호
• /
• pp.23-30
• /
• 2009

A lightcourt design is typically used to address issues concerning aesthetics, feeling, and mood. From the view point of environmental aspect, as an ecological shaft space, it plays a key role in controlling inner quality. In particularly, the lightcourt concept allows the exploitation of daylighting by bring natural light into the center of the building, thus eliminating dark deep spaces. Additionally, the lightcourt shades the inner space in summer. The amount of light available at the base of the lightcourt depends on a number of factors; translucency of the top, reflectance and the geometry of the space. In this paper is to exemplify a lightcourt configuration with a sloped wall. It promises the maximized a sense of freedom and daylighting availability. It is a matter of course that the lightcourt with open-top plays a role as a light source for the adjacent space to the lightcourt. A series of lighting simulation provides performance data of daylighting with changing photometric factors. For the case that a skylight is not available, an electric lighting design with metal halide lamps has been established to create luminous ceiling. As expected, a sloped lightcourt with open-top exposes its superiority of daylighting source. Ancillary considerations to enhance of daylighting potential for the adjacent space have been issued with performance data.

• 스마트미디어저널
• /
• 제5권1호
• /
• pp.30-37
• /
• 2016

In recent decades, the study of human brain function has dramatically increased thanks to the advent of Functional Magnetic Resonance Imaging. This is a powerful tool which provides a deep view of the activities of the brain. From fMRI data, the neuroscientists analyze which parts of the brain have responsibility for a particular action and finding the common pattern representing each state involved in these tasks. This is one of the most challenges in neuroscience area because of noisy, sparsity of data as well as the differences of anatomical brain structure of each person. In this paper, we propose the use of appropriate discriminant methods, such as Fisher Discriminant Ratio and hypothesis testing, together with strong boosting ability of Adaboost classifier. We prove that discriminant methods are effective in classifying cognitive states. The experiment results show significant better accuracy than previous works. We also show that it is possible to train a successful classifier without prior anatomical knowledge and use only a small number of features.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
• /
• pp.63-63
• /
• 2000

Deep submicron device contact hole에서의 bottom step coverage의 향상 및 SALICIDE공정의 필요성에 의해 collimated sputtering 및 ionized sputtering 등의 다양한 증착방법이 연구되어왔다. 반도체소자의 고집적화 및 미세화에 따라서 기존의 증착방법보다 더 높은 throughput을 가진 새로운 증착방법의 필요성이 대두되고 있다. Collimated sputtering방식으로 증착한 박막의 경우에는 증착속도가 느리고 collimator의 사용기간에 따른 공정조건의 변화가 단점으로 작용하였고 새로이 ionzied sputtering방식이 개발되었다. ionzied sputtering방식은 증착되는 금속 입자를 이온화시키고 기판에 바이어스를 걸어서 증착되는 입자의 방향성 및 증착속도의 향상을 얻을 수 있었다. 하지만 고집적도가 더욱 증가함에 따라서 더 높은 박막의 증착속도, bottom step coverage의 향상, 방향성의 향상과 더불어 증착되는 입자의 이온화 율의 증가 및 기존의 증착방식에 의한 박막보다 향상된 물성을 가진 박막증착의 필요성에 의해 hollow cathode magnetron sputtering방식이 연구되었다. HCM방식으로 titanium 박막을 증착하여 collimated sputtering 및 ionize sputtering 방식으로 증착한 titanium 박막과 물성을 비교해서 증착방식에 따른 박막물성의 차이를 연구하였다. 증착전에 기판온도는 30$0^{\circ}C$를 유지하였고 base pressure는 5.0$\times$10-9torr, working pressure는 5.7m torr로 유지하였다. power는 30kW를 가하여 50nm두께의 titanium박막을 증착하였다. 증착된 박막의 미세구조는 TEM 및 XRD로 분석하였다. HCM방식으로 증착한 titanium박막은 5nm두께의 비정질 층이 관찰되었고 ionized sputtering방식으로 증착한 titatnium박막에서 나타나는 것으로 보고된 silicon (002)와 titanium (0002) eledtron diffraction spot사이의 (10-10)spot은 관찰되지 않았다. 박막은 크고 작은 grain의 연속적 분포를 가졌고 HCM방식으로 증착한 titanium박막의 in-plane grain size가 다른 증착방식으로 증착한 박막에 비해 크게 관찰됨을 Plan-view TEM 분석을 통해서 확인되었다.

• 한국태양에너지학회 논문집
• /
• 제28권4호
• /
• pp.35-42
• /
• 2008

Besides genuine skin and clothes, it is called that building is third skin for us. That means the skin of buildings is the most important factor for our man-made environment. The issues in designing the building envelope include the insulation, infiltration, ventilation and bridging in windows. Getting light into the space safely and providing views to outdoor, additionally, are key things with the building envelope design. A deep-rooted preference for full view is still alive with large area of glass. Balcony expansion is legalized in apartment houses, which causes lots of environmental problems. Without balcony space, the adjacent space to unshaded window is exposed to the direct sun. A window can have many layers and the inner space can be utilized with an automatic blind system. Recently, the refurbished version of a double-glazed window system has been developed for the purpose of minimizing energy loss occurred around windows. For the better daylight control with equipped blind system, a set of adjustment technique of blind slats was tested in a mock-up building and recommended the detail operation. Not surprisingly, the optimized blind system can be oriented to enhance the uniformity in light distribution and direct glare from the sky as well..

• 대한임베디드공학회논문지
• /
• 제16권5호
• /
• pp.209-214
• /
• 2021

Panoptic segmentation, which is now widely used in computer vision such as medical image analysis, and autonomous driving, helps understanding an image with holistic view. It identifies each pixel by assigning a unique class ID, and an instance ID. Specifically, it can classify 'thing' from 'stuff', and provide pixel-wise results of semantic prediction and object detection. As a result, it can solve both semantic segmentation and instance segmentation tasks through a unified single model, producing two different contexts for two segmentation tasks. Semantic segmentation task focuses on how to obtain multi-scale features from large receptive field, without losing low-level features. On the other hand, instance segmentation task focuses on how to separate 'thing' from 'stuff' and how to produce the representation of detected objects. With the advances of both segmentation techniques, several panoptic segmentation models have been proposed. Many researchers try to solve discrepancy problems between results of two segmentation branches that can be caused on the boundary of the object. In this survey paper, we will introduce the concept of panoptic segmentation, categorize the existing method into two representative methods and explain how it is operated on two methods: top-down method and bottom-up method. Then, we will analyze the performance of various methods with experimental results.

• 방송공학회논문지
• /
• 제24권4호
• /
• pp.573-579
• /
• 2019

완전한 자율 주행에 이르기 위해서는 주변 환경을 인지하는 인지 능력이 사람보다 뛰어나야 한다. 자율 주행에서 주로 사용되는 $60^{\circ}$ 협각, $120^{\circ}$ 광각 카메라는 시야각에 따른 각각의 단점이 존재한다. 본 논문의 목적은 광각, 협각 카메라가 가진 각각의 단점을 극복하기 위하여, 다중화각 차량 전방 카메라 시스템을 이용하여 더 넓은 영역의 전방을 대상으로 더 정확히 객체를 인식할 수 있는 심층신경망 알고리즘을 개발하는 것이다. 광각, 협각 카메라로 취득된 데이터의 종횡비를 분석해 SSD(Single Shot Detector) 알고리즘을 수정하였고, 취득된 데이터를 학습하여 단안 카메라만을 사용할 때 보다 높은 성능을 달성하였다.

• 방송공학회논문지
• /
• 제23권6호
• /
• pp.760-767
• /
• 2018

첨단 운전자 지원 시스템(ADAS)은 차량 기술 분야에서 활발한 연구가 이루어지고 있는 기술이다. ADAS 기술은 직접적으로 차량을 제어하는 기술과 간접적으로 운전자에게 편의를 제공하는 기술로 나뉜다. 본 논문에서는 야간 도로 영상을 보정하여 운전자에게 시각적 편의를 제공하는 시스템을 제안한다. 제안하는 시스템은 전방 블랙박스 카메라로부터 촬영된 도로 영상을 입력받는다. 입력된 영상은 가로 축을 따라 세 부분으로 분할된 뒤 일괄적으로 이미지 변환 모듈을 통해 각각 낮 영상으로 변환된다. 변환된 영상은 다시 결합된 뒤 운전자에게 제공되어 시각적 편의를 제공한다. 본 논문의 실험 결과를 통해 제안한 시스템이 기존의 밝기 변환 알고리즘과 비교하여 우수한 성능을 보임을 입증한다.

• 천문학회보
• /
• 제44권1호
• /
• pp.44.4-44.4
• /
• 2019

The supernova remnant Cassiopeia A (Cas A) provides a unique opportunity to observe the fine details of the explosion of core-collapse supernova (SN). Previous optical and near-infrared (NIR) observations of Cas A have shown that the spatial distribution of the metal-enriched SN ejecta is very complicated, indicating that the SN explosion should have been asymmetric and turbulent, especially near the core. Recently, we obtained a long-exposure (~10 hr) image of Cas A by using the UKIRT 3.6-m telescope with a narrow-band filter centered at [Fe II] 1.644 um emission. This 'deep [Fe II] image' provides an unprecedented panoramic view of Cas A, revealing the distribution of dense SN ejecta over the entire remnant. We have carried out NIR multi-object spectroscopic observations of the dense ejecta knots in the northeastern (NE) and eastern (E) outer regions of the remnant using the MMIRS attached on the MMT 6.5-m telescope. A total of 67 ejecta knots are detected. By analyzing their spectra, we have found that the knots in the NE area show strong [S II]/[S III] and [Fe II] lines but little or no [P II] line, while those in the E outer region show strong [Fe II] lines but weak [S II]/[S III] lines. In this talk, we present the preliminary results of our NIR spectroscopic observations and discuss the implications.

• Nuclear Engineering and Technology
• /
• 제53권3호
• /
• pp.741-751
• /
• 2021

There has been a deep interest in trying to find better-performing fuel clad motivated by the desire to decrease the likelihood of the reactor barrier failure like what happened in Fukushima in recent years. In this study, the effect of move towards accident tolerant fuel (ATF) cladding as the most attracting concept for improving reactor safety is investigated for SMART modular reactor. These reactors have less production cost, short construction time, better safety and higher power density. The SiC and FeCrAl materials are considered as the most potential candidate for ATF cladding, and the results are compared with Zircaloy cladding material from reactor physics point of view. In this paper, the calculations are performed by generating PMAX library by DRAGON lattice physics code to be used for further reactor core analysis by PARCS code. The differential and integral worth of control and safety rods, reactivity coefficient, power and temperature distributions, and boric acid concentration during the cycle are analyzed and compared from the conventional fuel cladding. The rod ejection accident (REA) is also performed to study how the power changed in response to presence of the ATF cladding in the reactor core. The key quantitative finding can be summarized as: 20 ℃ (3%) decrease in average fuel temperature, 33 pcm (3%) increase in integral rod worth and cycle length, 1.26 pcm/℃ (50%) and 1.05 pcm/℃ (16%) increase in reactivity coefficient of fuel and moderator, respectively.

• 도시과학
• /
• 제9권2호
• /
• pp.45-50
• /
• 2020

The formation characteristics of calcium carbonates are closely related to the durability and mechanical properties of cement-based materials. In this regard, a deep understanding of the reaction pathway of calcium carbonates is critical. Recently, non-classical nucleation theory was summarized and it was presumed that prenucleation clusters are present. The formation of the prenucleation cluster at undersaturated condition (≈ 0.1 ml) in the present study was investigated via electrical characteristics of an electrolytic solution. Calcium chloride dihydrate (CaCl2·2H2O) and sodium carbonate (Na2CO3) were used as starting materials to supply calcium and carbonate sources, respectively. Furthermore, the reaction pathway of calcium carbonates was investigated by time-resolved polarization and depolarization characteristics of the electrolytic solution. The time-resolved polarization and depolarization tests were conducted by switching polarity with an interval of 20 seconds for 1 hr and by measuring the variation of electrical resistance. It can be inferred from the results obtained in the present study that the reactive constituent for the formation of calcium carbonates was mostly consumed in the period possibly associated with the prenucleation and the reaction pathways may be governed by the monomer-addition mechanism.