• Nuclear Engineering and Technology
• /
• 제55권8호
• /
• pp.2873-2878
• /
• 2023

The purpose of this study is to perform radiation monitoring by acquiring gamma images and real-time optical images for ^99mTc vial source using charge couple device (CCD) cameras equipped with the proposed compact gamma camera. The compact gamma camera measures 86×65×78.5 mm³ and weighs 934 g. It is equipped with a metal 3D printed diverging collimator manufactured in a 45 field of view (FOV) to detect the location of the source. The circuit's system uses system-on-chip (SoC) and field-programmable-gate-array (FPGA) to establish a good connection between hardware and software. In detection modules, the photodetector (multi-pixel photon counters) is tiled at 8×8 to expand the activation area and improve sensitivity. The gadolinium aluminium gallium garnet (GAGG) measuring 0.5×0.5×3.5 mm³ was arranged in 38×38 arrays. Intrinsic and extrinsic performance tests such as energy spectrum, uniformity, and system sensitivity for other radioisotopes, and sensitivity evaluation at edges within FOV were conducted. The compact gamma camera can be mounted on unmanned equipment such as drones and robots that require miniaturization and light weight, so a wide range of applications in various fields are possible.

• 천문학회지
• /
• 제42권5호
• /
• pp.125-134
• /
• 2009

We investigated the circumnuclear region of the Seyfert 2 galaxy NGC 5728, using the CFHT 3.6 m OASIS $[S_{II}]$, $[O_{III}]$ & $H\beta$ spectral images complemented with the IUE spectra. The physical condition of the circumnuclear zone has been derived: the gas density (indicated by $[S_{II}]$6716/31 ratio) around the C core is generally similar to that around the NW core, i.e., $\sim500cm^{-3}$. However, there appears to be evidence of a higher density shell in front of the NW core, $\sim10^4cm^{-3}$ at -250 km $s^-1$. The IUE $Si_{III}$]1892/$C_{III}$]1909 ratio implies a possible presence of a broad emission region of gas densities of $\sim10^{10}cm^{-3}$. The SE cone and surrounding area show several prominent features, while the NW cone does not show any particular structure: we identified three prominent blobs in the SE cone and one possible candidate in the NW cone. The outflow activities exist within the relatively large conic opening angle. We discussed the possibility of inflow or outflow activities of blobs found in the circumnuclear region of NGC 5728. The gas around two cores, two cones, and several blobs, is likely to be excited by the AGN hot source(s).

• 한국산업융합학회 논문집
• /
• 제23권3호
• /
• pp.481-489
• /
• 2020

Safety and security during the handling of hazardous materials is a great concern for anyone in the field. One driving point in the security field is the ability to detect the source of the danger and take action against it as quickly as possible. Via the usage of a fully convolutional network, it is possible to create the label map of an input image, indicating what object is occupying the specific area of the image. This research employs the usage of U-net, which was constructed in biomedical field segmentation to segment cells, instead of the original FCN. One of the challenges that this research faces is the availability of ground truth with precise labeling for the dataset. Testing the network after training resulted in some images where the network pronounces even better detail than the expected label map. With better detailed label map, the network might be able to produce better segmentation is something to be studied in further research.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2020년도 학술발표회
• /
• pp.114-114
• /
• 2020

Water contamination in a water distribution network (WDN) is harmful since it directly induces the consumer's health problem and suspends water service in a wide area. Actions need to be taken rapidly to countermeasure a contamination event. A contaminant source ident ification (CSI) is an important initial step to mitigate the harmful event. Here, a CSI approach focused on determining the contaminant intrusion possible location and time (PLoT) is introduced. One of the methods to discover the PLoT is an inverse calculation to connect all the paths leading to the report specification of a sensor. A filtering procedure is then applied to narrow down the PLoT using the results from individual sensors. First, we spatially reduce the suspect intrusion points by locating the highly suspicious nodes that have similar intrusion time. Then, we narrow the possible intrusion time by matching the suspicious intrusion time to the reported information. Finally, a likelihood-score is estimated for each suspect. Another important aspect that needs to be considered in CSI is that there are inherent uncertainties, such as the variations in user demand and inaccuracy of sensor data. The uncertainties can lead to overlooking the real intrusion point and time. To reflect the uncertainties in the CSI process, the Monte-Carlo Simulation (MCS) is conducted to explore the ranges of PLoT. By analyzing all the accumulated scores through the random sets, a spread of contaminant intrusion PLoT can then be identified in the network.

• 한국농촌건축학회논문집
• /
• 제24권4호
• /
• pp.41-48
• /
• 2022

The purpose of this study is to present the implications of the rural living area setting and rural spatial structure analysis of the rural spatial strategy plan through case analysis. Following the decentralization of autonomy and the promotion of the transfer of state affairs to local areas, some of the general agricultural and fishing village development projects of the Ministry of Agriculture, Food and Rural Affairs were transferred to local areas. In addition, in 2020, the Ministry of Agriculture, Food and Rural Affairs introduced a rural agreement system for 113 cities and counties. However, since the understanding of the field is still low, this study attempted to present implications through a case analysis of the structure of rural space and the establishment of rural living areas in three local governments in Chungcheong. As a result of the study, in the stage of establishing the living zone, it is necessary to comprehensively review the contents reviewed in the analysis of the current status and conditions. However, the two local governments had insufficient interpretation of the axis by function and the establishment of the base area, or were using the upper plan as it was. Second, the source of the data used in the survey on the distribution status of living SOC facilities is unclear. Since the distribution status of living SOC facilities overlaps with accessibility analysis, OD data analysis, and resident survey results and is used as the basis for setting living areas, the data source should be clearly marked, and verification should be possible. Third, amenity (facility) resources were classified and analyzed according to the conditions and characteristics of local governments. The local government that applied the guidelines as they were was A local government, and the remaining local governments conducted surveys and analysis according to the current status. Forth, since the establishment of the rural living area is the minimum unit supported by government policies through future rural agreements, it is necessary to distinguish them based on quantitative standards in the process of establishing them. Only one case area presented clear grounds and standards, and the rest of the case areas presented standards but are based on non-quantitative standards. In order for rural agreements to be sustainable in the future and benefit local residents, it is necessary to use or establish a government-level institution that can collect and produce objective data. In addition, it is necessary to find ways to specify and standardize the standards for setting the living area and specify them in the guidelines.

• Asian Journal of Atmospheric Environment
• /
• 제6권1호
• /
• pp.14-22
• /
• 2012

This paper is focused on the comprehensive and detailed interpretation for the chemical transformation of individual Asian dust (hereafter called "AD") particles during long-range transport from source regions to receptor area. A multi-stage particle sampler was operated at a ground-based site in Taean, Korea directly exposed to the outflow of air masses from China during AD period in April 2003. Both quantitative and qualitative analyses for size-classified individual particles were carried out by a microbeam X-ray fluorescence (XRF) method and a microbeam Particle Induced X-ray Emission (micro-PIXE), respectively. Among major characteristic elements, the elemental masses of soil derived components, sulfur, and chloride varied as a function of particle size showing the monomodal maximum with a steeply increasing at 3.3-4.7 ${\mu}m$ particle size. Although the details on chemical composition of AD particle collected on a straight line from source area to our ground-based site are needed, a large amount of Cl coexisted in and/or on AD particles suggests that AD particles collected in the present study might be actively engaged in chemical transformation by sea-salt and other Cl containing pollutants emitted from the China's domestic sources. Through the statistical analyses it was possible to classify individual AD particles into six distinct groups. The internally mixed AD particles with Cl, which has various sources (e.g., sea-salt, coal combustion origin HCl, gaseous HCl derived from the adsorption of acids to sea-salt, and Cl containing man-made particles) were thoroughly fractionated by the elemental spectra drivened by the double detector system of micro-PIXE.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2004년도 학술대회 논문집
• /
• pp.305-308
• /
• 2004

There are ground facility of maintenance in house electric facility of infra maintenance electric home appliances having used multifariousness in house, that use electric energy of common source for equipment. The body of building such as the reinforced concrete construction is structurally united, and the electric resistance is also small. It is possible that those foundations have contacted the ground at large surface area and that it substitutes the building construction body for the earth electrode. This is called "the structure earthing". This method has been defined at electrical facilities technical standards and KS in our country, and it has been used in various quarters practically. However, in our country, there is no example of using the foundation of the house as substitution earth electrode practically, and the means of the evaluation as electrode has not been established either. Then, in this paper, basic research for utilizing foundation of the house as substitution earth electrode is carried out.

• 대한방사선치료학회지
• /
• 제2권1호
• /
• pp.31-40
• /
• 1987

In the case of designing a high dose rate remote controlled afterloading treatment room with existing hospital facilities. We must construct the effective protective barriers so as to reduce the primary and scattered radiation up to the maximum permissible dose level. It is difficult to reinforce the barrier thickness of the shielding requirements because of the limited space and the problem of the existing building structure at the surrounding area. Therefore we can reduce the intensity of primary radiation to the required degree at the location of interest with installing the appropriate I shaped Pb barriers between the radiation source and the shielding wall of the concrete. As a result, it was possible to reduce the intensity of the primary radiation below the M.P.D level by using additional Pb barriers instead of increasing thickness of concrete wall.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
• /
• pp.848-851
• /
• 2006

Green vegetation is one of the most critical factors for environment conditions thorough modulating evapotranspiration and absorption of solar radiation. Thus, fractional green vegetation cover (FVC) plays an important role in observing and managing environment. Remote sensing provides a seemingly obvious data source for quantifying FVC over large area. Therefore we compared a set of methods for estimating FVC using hyperspectral remote sensing data. For our study, we used Hyperion imagery acquired in April, 2002. In order to achieve our efforts, we analyzed simple NDVI-based method and spectral mixture analysis (SMA) models that were applied a variety of combinations of possible endmembers.

• 환경위생공학
• /
• 제7권2호
• /
• pp.69-82
• /
• 1992

Air pollution in urban areas of Korea is considered in significantly serious level because of population exceeding the capacity and diversified facilities for the activities in socioeconomic field, education, politics and even cultural society in confined areas. Korea is one of the most populated countries and the largest five cities occupy 2.4% of total area but 45% of total population. Patterns of urban air pollution are also changing due to the change of emission sources and fuel usage. Essential recovery of urban environment in Korea has become extremely difficult and necessitates enormous investment. Accurate understanding of problems should be pursued for the efficient and effective improvement of the environment. In this article, air pollution phenomena in urban areas are analyzed mainly with respect to recent urban air pollution trend and pollution sources and possible control strategies are discussed : 1) source control-stationary and mobile, 2) air quality management strategies, 3) research and development.