• Architectural research
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• v.22 no.4
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• pp.123-133
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• 2020

Light is an essential environmental element for elderly people to do various activities. At senior welfare centers, healthy indoor lighting is especially necessary because the facilities are used by the elderly to perform their mostly indoor activities. The purpose of this study is to evaluate light environments at senior welfare centers for well-being lighting characteristics. We based the study on the 'Biophilia' theory, a concept related to health from happiness. Thus, this study is mainly based on literary review and survey research. For this, we conducted a location focused field study to identify the current state of the lighting environments at senior welfare centers in Busan, South Korea. First, we constructed structural questionnaire to evaluate lighting environment based on 'Light and Space' biophilia theory. Then, to survey subjective evaluation, the participant of research included total of 122 senior welfare center users. Based on the results of this research, the conclusions are as follows; 1) overall, it seems that the overall result of the light environmental evaluation seems to be high because the evaluated facilities in the case survey in large-scale were recently built elderly welfare centers. 2) most of the healing design elements are focused on the introduction of natural light and psychological influence. The satisfaction with actual natural light is evaluated to be high. Although shadow and reflected light are very important in discrimination and recognition of indoor space and wayfinding, the evaluation of reflected light and shadow was low for the study. 3) items that are related to the functionality of the light were highly evaluated, while the items that are related to the spatiality of the light were rated poorly. This study has its significance when examining the effects of light environments within the welfare center form of the perspective of senior citizens. It can be referenced when reconsidering the recognition of light environment as a major consideration factor to establish a desirable senior welfare center environment.

• Journal of radiological science and technology
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• v.12 no.1
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• pp.25-29
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• 1989

This paper investigated on influence on the distinguishability of renal stone in the accordance with thickness of object, x-ray tube voltage and base density. In the relationship between object and renal stone shadow, object and tube voltage, the obtained results can be summarized as the following. 1. When thickness of object was thin, the distinguishability increased in base density $2.0{\sim}2.5$, but for adults was best shown in base density 1.5. 2. In the relationship between object and tube voltage, the distinguishability increased at lower tube voltages ($50{\sim}60\;kVp$), using grid. As mentioned above, it was thought that this method was very effective in describing the phenomena of renal stone in film density 1.5, tube voltages 60 kVp.

• Journal of ILASS-Korea
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• v.2 no.1
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• pp.46-51
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• 1997

In this study, spray characteristics of the pressure swirl atomizer have teen investigated. Four atomizers with the different orifice diameter and five tangential ports with the different inlet number were fabricated. For the purpose of the measurement of the mean drop sine, Malvern particle sizer was used. And also discharge coefficient was measured and spray cone angle was measured by using shadow graphy method. As a result when the injection pressure was increased, mean drop size was decreased. And the dominant factor which influence on the spray characteristics of pressure swirl atomizer was orifice diameter.

• Journal of ILASS-Korea
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• v.11 no.2
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• pp.105-112
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• 2006

A unique feature of fluidic atomizers is that the nozzle geometry produces a thin capillary Jet which is forced to oscillate on a 2-dimensional plane through the use of a passive feedback mechanism. The objective of the current work is to characterize the influence of the stagnation pressure at the nozzle exit, jet oscillation and stretching on the breakup properties of the capillary ligament. To achieve this, shadow graph technique is used to measure size, shape, velocity and the number density of the droplets as a function of the position within the spray fan. The breakup length, defined as the radial distance from the breakup point, is analyzed as a function of the non-dimensional parameters. Finally, a kinematic model is developed to simulate the breakup of the oscillating jets at low stagnation pressures. Using the existing jet breakup theories, the model is used to predict the size and diameter distribution of the droplets after primary atomization.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.32-34
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• 2007

The X-ray projection system has long been used for steel-tube inspection and weld monitoring. The thickness of tubes and welded areas is based on the evaluation of radiographic shadow projections. The traditional tangential measurement estimates the distance of border lines of the projected wall shadows of a tube onto a radiographic image detector. The detected image in which although there is a variety of noise may be sectioned into several partitions according to its specific blocks. Imaging noise originates from most of elements of the system, such as shielding CCD camera, imaging screen, X-ray source, inspected object, electronic circuits and etc. The tangential projection incorrectness and noise influence on imaging quality. In this paper we first sectionalize the X-ray image on the basis of vertical contrast difference. And next functional and statistic analysis are carried on at each region. Geometrical distance and unsharpness of the edge caused by visual evaluation uncertainties are also discussed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.3
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• pp.210-216
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• 1984

An investigation of the effects of the size of mixing region determined by changing the position of fuel injection has been carried out. Measurements were made: the distribution of temperature and concentration profiles of the stable gas species, nitrogen oxide and total hydrocarbon in the flames. The results of this investigation show that variations of the size of mixing region produce major changes to the three type flow fields which significantly influence pollutant (NO, CO and THC) formation and energy release.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.7
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• pp.1157-1166
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• 2008

This paper presents a new approach for the evaluation of location marginal prices (LMPs) considering demand-side bidding (DSB) in a competitive electricity market. The stabilization of the electric power supply and demand balance is one of the major important activities in electric power industry. In this paper, we present an analytical method for calculation of LMPs considering DSB, which has opportunity to compete with generating units, as England & Wales Pool's DSB scheme[1]. Also, we propose a new approach that LMP considering DSB is divided into three components. The proposed approach can be used for the evaluation of demand-side bidding into the electricity market and the assessment of the influence of DSB on total production costs and LMPs as well as three components.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.281-284
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• 2004

광범위한 면적의 토지피복분류를 관찰하는데 유용하게 사용되고 있는 NOAA AVHRR 자료는 자료의 방대한 양과 구름에 의한 영향을 없애기 위하여 일반적으로 MVC(Maximum Value Composite) 처리를 하여 사용한다. 그러나 수신당시의 여러 가지 환경인자(구름, 저주파 노이즈, 산란, 구름의 그림자 등)에 의하여 각 채널의 패턴이 변화하여 오독을 할 위험성이 있다. 특히 그림자의 영향에 의해 측정치가 변화하는 NOAA 위성의 채널2영역에서는 이러한 특징이 두드러진다. 따라서 본 연구에서는 지상에서 실제로 측정한 자료를 기초로 하여 NOAA 영상자료에서 구름으로 인한 그림자의 영향에 관하여 조사하였고, 한 픽셀안에서 그림자의 영향이 60%이상이 될 경우에는 오독의 가능성이 높은 것으로 나타났다.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.210-212
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• 2019

태양광발전에서 PV panel의 출력 전압 및 전류는 제한적이기 때문에, 필요로 하는 전원 조건을 충족시키기 위하여 PV panel을 직병렬로 연결하여 PV array를 구성한다. 이때, PV array에 부분적인 그림자가 발생할 경우 최대발전전력은 PV array의 접속 구조와 블록킹 다이오드 유무에 따라 달라진다. 본 논문에서는 PV panel의 직병렬 접속에 따른 PV array의 6가지의 접속 구조와 블록킹 다이오드 유무를 고려하여, 부분적인 그림자가 발생할 경우 발전전력을 극대화할 수 있는 최적의 접속 구조를 제시하고 시뮬레이션과 실험을 통해 검증하였다.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1343-1356
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• 2022

Clouds or shadows are the most problematic when monitoring crops using optical satellite images. To reduce this effect, a composite algorithm was used to select the maximum Normalized Difference Vegetation Index (NDVI) for a certain period. This Maximum NDVI Composite (MNC) method reduces the influence of clouds, but since only the maximum NDVI value is used for a certain period, it is difficult to show the phenomenon immediately when the NDVI decreases. As a way to maintain the spectral information of crop as much as possible while minimizing the influence of clouds, a Score-Based Composite (SBC) algorithm was proposed, which is a method of selecting the most suitable pixels by defining various environmental factors and assigning scores to them when compositing. In this study, the Sentinel-2A/B Level 2A reflectance image and cloud, shadow, Aerosol Optical Thickness(AOT), obtainging date, sensor zenith angle provided as additional information were used for the SBC algorithm. As a result of applying the SBC algorithm with a 15-day and a monthly period for Dangjin rice fields and Taebaek highland cabbage fields in 2021, the 15-day period composited data showed faster detailed changes in NDVI than the monthly composited results, except for the rainy season affected by clouds. In certain images, a spatially heterogeneous part is seen due to partial date-by-date differences in the composited NDVI image, which is considered to be due to the inaccuracy of the cloud and shadow information used. In the future, we plan to improve the accuracy of input information and perform quantitative comparison with MNC-based composite algorithm.