• Journal of Conservation Science
• /
• v.35 no.3
• /
• pp.209-216
• /
• 2019

Lead isotope ratios in horse-shaped bronze buckles excavated from the Songjeol-dong site in Cheongju and the mid-western region of the Korean Peninsula have been determined by thermal ionization mass spectrometry. The lead isotope ratios of the samples with data provenance were plotted in zone 3 of the South Korean galena map. The results indicated that the horse-shaped bronze buckles could be made using galena located in the same area as the archaeological site. These results can be used as basic data for comparison purposes in future studies on the manufacturing technology and provenance of bronze artifacts.

• The Journal of the Acoustical Society of Korea
• /
• v.42 no.5
• /
• pp.395-401
• /
• 2023

Sound Event Detection (SED) aims to identify not only sound category but also time interval for target sounds in an audio waveform. It is a critical technique in field of acoustic surveillance system and monitoring system. Recently, various models have introduced through Detection and Classification of Acoustic Scenes and Events (DCASE) Task 4. This paper explored how to design optimal parameters of DenseNet based model, which has led to outstanding performance in other recognition system. In experiment, DenseRNN as an SED model consists of DensNet-BC and bi-directional Gated Recurrent Units (GRU). This model is trained with Mean teacher model. With an event-based f-score, evaluation is performed depending on parameters, related to model architecture as well as model training, under the assessment protocol of DCASE task4. Experimental result shows that the performance goes up and has been saturated to near the best. Also, DenseRNN would be trained more effectively without dropout technique.

• Journal of the Korean Society of Groundwater Environment
• /
• v.6 no.1
• /
• pp.23-32
• /
• 1999

A new numerical method using solution-adaptive grids (SAG) is developed to solve the Richards' equation (RE) for unsaturated flow in porous media. Using a grid generation technique, the SAG method automatically redistributes a fixed number of grid points during the flow process, so that more grid points are clustered in regions of large solution gradients. The method uses the coordinate transformation technique to employ a new transformed RE, which is solved with the standard finite difference method. The movement of grid points is incorporated into the transformed RE, and therefore all computation is performed on fixed grid points of the transformed domain without using any interpolation techniques. Thus, numerical difficulties arising from the movement of the wetting front during the infiltration process have been substantially overcome by the new method. Numerical experiments for an one-dimensional infiltration problem are presented to compare the SAG method to the modified Picard method using a fixed grid. Results show that accuracy of a SAG solution using 41 nodes is comparable with the solution of the fixed grid method using 201 nodes, while it requires only 50% of the CPU time. The global mass balance and the convergence of SAG solutions are strongly affected by the time step size (Δt) and the weighting parameter (${\gamma}$) used for generating solution-adaptive grids. Thus, the method requires automated readjustment of Δt and ${\gamma}$ to yield mass-conservative and convergent solutions, although it may increase computational costs. The method can be effective especially for simulating unsaturated flow and other transport problems involving the propagation of a sharp-front.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.12A
• /
• pp.1883-1890
• /
• 1999

Wireless communication in an urban area, the accurate prediction of wave propagation characteristics are very important to determine communication service areas, select optimal base-stations, and design cells, etc. The CCIR model is a propagation prediction model using a shadowing by the buildings in an urban area. This model represent the shadowing rate by the means of the effect of shadowing between base-station and mobile unit in a shaped linear plane. But, This one occurred a lot of prediction error because it did not consider that density area by the buildings and terrain configurations by the hill and mountain on Line-Of-Sight. In this thesis, an improved propagation prediction model is proposed to reduce prediction error. We presents a new equation, which is using the SAS. This equation is associated with the shadow height by the buildings that considers the topology and the number of blocks that can affect the building shadow in the Line-Of-Sight. We measure the received electrical field level of base-station that high density area, medium density area, and low density area, and then compare and analysis the result to prediction of CCIR model and proposed model. The result compared with the measurement, the proposed model has the improvement of 9.71dB in a high density area, 9.66dB in a medium density area, and 4.02dB in a low density area better than the CCIR model. The result compared with the measurement, the proposed model has the improvement of 9.71dB in a high density area, 9.66dB in a medium density area, and 4.02dB in a low density area better than the CCIR model.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.25 no.4
• /
• pp.107-118
• /
• 2022

As connected and automated driving(CAD) technology is entering its commercialization stage, service platforms providing CAD-based mobility services have increased these days. However, CAD-baded mobility services with these platforms need more consideration for the demand for mobility services when determining target areas for CAD-based mobility services because current CAB-based mobility design focus on driving performance and driving stability. For a more efficient design of CAD-based mobility services, we analyzed the applicability for the introduction of CAD-based mobility services in terms of driving difficulty of CAD and demand patterns of current non-CAD based-mobility services, e.g., taxi, demand-responsive transit(DRT), and special transportation systems(STS). In addition, for the spatial analysis of the applicability of the CAD-based mobility service, we propose the Index for Autonomous Driving Applicability (IADA) and analyze the characteristics of the spatial distribution of IADA from the network perspective. The analysis results show that the applicability of CAD-based mobility services depends more on the demand patterns than the driving difficulty of CAV. In particular, the results show that the concentration pattern of demand in a specific road link is more important than the size of demand. As a result, STS service shows higher applicability compared to other mobility services, even though the size of demand for this mobility service is relatively small.

• Journal of Korean Society of Disaster and Security
• /
• v.15 no.3
• /
• pp.41-46
• /
• 2022

Recently, the scale of flood damage occurring in urban areas is increasing due to climate change and urbanization, so various flooding analysis techniques are needed. In the Sadangcheon Stream basin, which has been continuously flooded since 2010, a basic plan for improving drainage was established using XP-SWMM and measures to prevent flooding were proposed. However, in the process of inundation analysis, the analysis considering the city's buildings was not conducted, resulting in a problem that the degree of flooding damage tends to be overestimated. Therefore, in this study, XP-SWMM was used to compare and analyze cases where buildings were not considered and designated as inactive areas. As a result of the study, it was analyzed if the building was not considered, the flood damaged area was 271,100 m² and the depth of submersion was 0.15 m, and if the building was considered inactive area, the flood damaged area was 172,900 m² and the depth of submersion was 0.32 m that it is under-estimated about 36% and an flow velocity around the building increased from 1.62 m/s to 1.83 m/s about 1.12 times.

• The Transactions of the Korea Information Processing Society
• /
• v.13 no.2
• /
• pp.48-59
• /
• 2024

As functions that support virtualization on their own in hardware are developed, user applications having various workloads are operating efficiently in the virtualization system. SR-IOV is a virtualization support function that takes direct access to PCI devices, thus giving a high I/O performance by minimizing the need for hypervisor or operating system interventions. With SR-IOV, network I/O acceleration can be realized in virtualization systems that have relatively long I/O paths compared to bare-metal systems and frequent context switches between the user area and kernel area. To take performance advantages of SR-IOV, network resource management policies that can derive optimal network performance when SR-IOV is applied to an instance such as a virtual machine(VM) or container are being actively studied.This paper evaluates and analyzes the network performance of SR-IOV implementing I/O acceleration is compared with Virtio in terms of 1) network delay, 2) network throughput, 3) network fairness, 4) performance interference, and 5) multi-network. The contributions of this paper are as follows. First, the network I/O process of Virtio and SR-IOV was clearly explained in the virtualization system, and second, the evaluation results of the network performance of Virtio and SR-IOV were analyzed based on various performance metrics. Third, the system overhead and the possibility of optimization for the SR-IOV network in a virtualization system with high VM density were experimentally confirmed. The experimental results and analysis of the paper are expected to be referenced in the network resource management policy for virtualization systems that operate network-intensive services such as smart factories, connected cars, deep learning inference models, and crowdsourcing.

• Korean Journal of Heritage: History & Science
• /
• v.40
• /
• pp.207-241
• /
• 2007

This paper investigates the royal collection of paintings and calligraphy during King Gojong's (高宗) reign (1897~1907) based on the function of the Jipgyeong-dang Hall (緝敬堂), situated at "sleeping realm (寢殿)," Gyeongbok Palace. Using the surviving palace records and art works this study argues that the date of building the hall is approximately confined to the year of 1890. Not being matched with the general opinion that the Jipgyeong-dang Hall was used for the official meeting with envoys, this hall functioned as the main place for royal audience and the storehouse for archives. The role of Gojong as collector and patron was essential not only to the maintenance of the collection but also to the strengthening of royal authority just before the Japanese annexation in 1910. The specific titles of the collection at this hall can be verified through the Catalogue of the Books, Paintings, and Calligraphy Exposed to the Sun at Jipgyeong-dang Hall (緝敬堂曝曬書目) dating to the nineteenth century. The records of the catalogue inform us that more than 1,000 paintings and pieces of calligraphy, inkrubbings from old steles, manuals for painting, and encyclopedia concerning art theories from Korea, China, and Japan were preserved there. The collection of Jipgyeong-dang Hall resulted from Gojong's policy to foster the collection of contemporary Chinese and Japanese art works and various catalogues. Standing behind the Gyeongbok Palace, the Jibok-jae Hall (集玉齋) also preserved the diverse sources of practical learning, as did the Jipgyong-dang Hall for Gojong. The enormous royal collections by Gojong might have been constructed in accordance with the royal artistic taste and the artistic milieu of the late Joseon period. The surviving royal catalogues confirm this assumption as documentary evidence.

• Journal of fish pathology
• /
• v.8 no.2
• /
• pp.119-134
• /
• 1995

To induce an overpopulated melanomacrophage centers(MMCs) within spleen and kidney in tilapias, two methods were applied through the intraperitoneal inoculation of V. anguillarum FKC with a repeated dose of saline(the 1st induction group), and of colloidal carbon (the 2nd induction group). In the 1st group, both number and size of MMCs were slightly increased in spleen and head kidney. However in the 2nd group the two hemopoietic tissues were nearly occupied with quite a large number of MMCs. Regardless of induction groups, many of MMCs were confined within the walls of blood vessels in the spleen. Especially in the 2nd group, the MMCs without fibrous capsules often had concentrically or eccentrically located, thin-walled lumens of vessels, which strongly suggests to be ellipsoids. In head kidney, nearly all MMCs were located within or just around the lymphocytic areas but the precise relationship to blood vessel wall was not obvious. Despite of such overpopulated MMCs, no histopathological degenerative findings in hemopoetic parenchymas of both organs were recognized. To evaluate the effect on defensive function, tilapias of the 2nd group were challenged with E. tarda. Susceptabilities to E. tarda were never increased but rather significantly decreased compared to control. Weekly antibody titres in sera were determined for all induction groups, in which the titres in the 1st and 2nd groups were 4 or 8 times higher than in the control, and then remained high until the 4th week. Also with the hemopoietic function, cellular compositions of peripheral blood were analyzed at weekly intervals but no significant changes resulted. From those results, it is suggested that overcrowding of MMCs would not lead to any morphological as well as functional deteriorations of spleen and head kidney but have an intimate association with enhancement of protective immune system in tilapias.

• 지역과문화
• /
• v.7 no.2
• /
• pp.173-202
• /
• 2020

This study aims to enhance the family-friendliness of the region by examining the relationship between family relations and the community environment, and objectively comparing the local environment surrounding the family. To this end, we reviewed the areas of socio-cultural and economic sectors that affect the family relationship satisfaction, and in particular, analyzed the trend of changes in regional index by utilizing the Korean Family Happiness Composite Index (KFHCI) developed as a community indicators. This index utilizes community indicators published in the National Statistical Portal's "e-Region indicators," and these variables are related to family relationship satisfaction. Therefore, this study compared the seven areas of the Family Happiness Composite Index (Population Family, Health Culture, Education, Income Consumption, Employment Labor, Housing Transportation, Environment and Social Integration) by region, and examined the trends for 10 years. According to the study, the average score of KFHCI's entire region was rising from 2008 to 2018. Overall, the community environment that affects family relationship satisfaction is also improving. The regions belonging to the upper level were Jeonnam, Gangwon, Chungnam, Jeonbuk, and Gyeongbuk. Areas belonging to the lower level are Seoul, Busan, Daegu, Incheon, and Gwangju. In almost sectors, the lower-level regions did not have sufficient physical infrastructure compared to population density and over-density, and improved little by little, but not enough to reflect the needs of local people and improve the quality of life. In the future, we should develop more regular and complementary indicators to develop customized policies for each region that can improve the quality of family relationships. It will also be necessary to study the impact of each index field when a socioeconomic crisis occurs due to social disasters, and try to change indicators