• The Journal of the Acoustical Society of Korea
• /
• v.28 no.5
• /
• pp.409-415
• /
• 2009

The head-related transfer function (HRTF), which has an important role in virtual sound localization has different characteristics across the subjects. Measuring HRTF is very time-consuming and requires a set of specific apparatus. Accordingly, HRTF customization is often employed. In this paper, we propose a method to search an adequate HRTF from a set of the HRTFs. To achieve rapid and reliable customization of HRTF, all HRTFs in the database are partitioned, where a binary search tree was employed. The distortion measurement adopted in HRTF partitioning was determined in a heuristic way, which predicts the differences in perceived sound location well. The DC-Davis CIPIC HRTF database set was used to evaluate the effectiveness of the proposed method. In the listening test, where 10 subjects were participated, the stimuli filtered by the HRTF obtained by the proposed method were closer to those by the personalized HRTF in terms of sound localization. Moreover, performance of the proposed method was shown to be superior to the previous customization method, where the HRFT is selected by using anthropometric data.

• Journal of Korean Foot and Ankle Society
• /
• v.28 no.1
• /
• pp.27-30
• /
• 2024

Several types of soft tissue masses occur in the lower extremities. A mass associated with blood vessels is often difficult to diagnose. A 15-year-old male patient visited the author's hospital with discomfort and edema in his right calf that had persisted for six months. A physical examination showed no palpable mass other than mild edema. Three masses were found during the ultrasound scan along the small saphenous vein. The masses had a cyst-like appearance and were filled with thrombus. In duplex ultrasound, vascular reflux was represented inside the masses. During surgery, it was suspected that vascular deformation occurred in the small saphenous vein, and simple ligation and resection treatments were performed. The patient was finally diagnosed with venous aneurysms accompanied by thrombosis based on the histology tests. The symptoms disappeared after surgery, and there were no recurrences or unusual findings at the follow-up one year later. Venous aneurysms occurring in the superficial veins of the lower extremities are rarely reported, but treatment and diagnosis are important. This paper reports a case of an aneurysm on the small saphenous vein.

• Journal of Life Science
• /
• v.26 no.11
• /
• pp.1259-1268
• /
• 2016

In this study, we investigated antimicrobial peptide from the acidified muscle extract of Mytilus coruscus, which mostly inhabits China, Japan, and Korea, to develop a natural product-derived antibiotics substitution in terms of its abuse and restriction. Antimicrobial peptide was purified by $C_{18}$ reversed-phase high-performance liquid chromatography and was detected as having a molecular mass of 6,701 Da by MALDI-TOF/MS. The N-terminal amino acid sequence of the purified peak was obtained from edman degradation, and 20 identified residues shown 100% identity with the N-terminus region of sperm-specific protein and protamine-like PL-II/PL-IV precursor of Mytilus californianus. We also identified 60 open-reading frame (ORF) encoding amino acids with 183 bp of purified peptide based on the obtained amino acid residues. The amino acid sequence of ORF showed 100% and the nucleotide sequence revealed 97.2% identity with the protamine-like PL-II/PL-IV precursor of Mytilus californianus. Synthesized antimicrobial peptide showed antimicrobial activity against gram-positive bacteria, including Bacillus cereus (minimal effective concentration [MEC], $20.8{\mu}g/ml$), Bacillus subtilis (MEC, $0.2{\mu}g/ml$), Streptococcus mutans (MEC, $0.2{\mu}g/ml$), gram-negative bacteria including Pseudomonas aeruginosa (MEC, $5.7{\mu}g/ml$), Escherichia coli (MEC, $2.6{\mu}g/ml$) and fungi, Candida albicans (MEC, $56.3{\mu}g/ml$). In addition, synthesized peptide showed stable activities under heat and salt conditions against gram-positive and gram-negative bacteria, but was inhibited by salt against only C. albicans. With these results, isolated peptide from M. coruscus could be an alternative agent to antibiotics for defending against pathogenic microorganisms, and helpful information to understand the innate immune system of marine invertebrates.

• Korean Journal of Remote Sensing
• /
• v.39 no.6_1
• /
• pp.1413-1425
• /
• 2023

The increasing frequency of wildfires due to climate change is causing extreme loss of life and property. They cause loss of vegetation and affect ecosystem changes depending on their intensity and occurrence. Ecosystem changes, in turn, affect wildfire occurrence, causing secondary damage. Thus, accurate estimation of the areas affected by wildfires is fundamental. Satellite remote sensing is used for forest fire detection because it can rapidly acquire topographic and meteorological information about the affected area after forest fires. In addition, deep learning algorithms such as convolutional neural networks (CNN) and transformer models show high performance for more accurate monitoring of fire-burnt regions. To date, the application of deep learning models has been limited, and there is a scarcity of reports providing quantitative performance evaluations for practical field utilization. Hence, this study emphasizes a comparative analysis, exploring performance enhancements achieved through both model selection and data design. This study examined deep learning models for detecting wildfire-damaged areas using Landsat 8 satellite images in California. Also, we conducted a comprehensive comparison and analysis of the detection performance of multiple models, such as U-Net and High-Resolution Network-Object Contextual Representation (HRNet-OCR). Wildfire-related spectral indices such as normalized difference vegetation index (NDVI) and normalized burn ratio (NBR) were used as input channels for the deep learning models to reflect the degree of vegetation cover and surface moisture content. As a result, the mean intersection over union (mIoU) was 0.831 for U-Net and 0.848 for HRNet-OCR, showing high segmentation performance. The inclusion of spectral indices alongside the base wavelength bands resulted in increased metric values for all combinations, affirming that the augmentation of input data with spectral indices contributes to the refinement of pixels. This study can be applied to other satellite images to build a recovery strategy for fire-burnt areas.

• Geophysics and Geophysical Exploration
• /
• v.8 no.4
• /
• pp.280-286
• /
• 2005

Geological sequestration of carbon dioxide ($CO_2$) is one of the most effective strategies far long-term removal of greenhouse gas from atmosphere. This paper reviews three projects for the $CO_2$ sequestration in geological formation. A unique $CO_2$ injection into a marine aquifer has been successfully monitored with repeated surface seismic measurements in the North Sea Sleipner West field. The seismic images reveal the extent and internal shape of the $CO_2$ bubble. Massive miscible $CO_2$ has been injected into a complex fractured carbonate reservoir at the Weyburn oil filed. High-resolution time-lapse P-wave data were successfully obtained to map the features of $CO_2$ movements within the two thin zones of different lithology. From the time-lapse crosswell EM imaging at the Lost Hills oil field in central California, U.S.A., the replacement of brine with $CO_2$ has been confirmed through a decrease of conductivity. The conductivity image was successfully compared with induction logs observed in the two wells.

• Journal of the Korean Society for Library and Information Science
• /
• v.52 no.3
• /
• pp.363-390
• /
• 2018

The libraries and social welfare centers carry out various programs for the information poor. The libraries have focused on accessing and utilizing information, while social welfare centers have centered on improving the quality of life. This study have investigated as follows. Firstly, this study examined the cooperation model between libraries and social welfare centers or librarians and social workers in public libraries in Korea and California, USA, and analyzed the international library policies and guidelines in literature review. Through the definition of terms and related concepts, we confirmed the range of the information poor in this study. Secondly, this study executed to interview librarians and social workers in Korea and USA about the way of cooperation for the information poor. These interviews have been understood the public library outreach programs in California and the program of the National Library for Children and Young Adults' Out of School Youth Reading Program (2018). Finally, this study suggested the core elements to be considered in developing a library outreach model for the information poor based on the implications derived from literature review and interviews.

• The Journal of the Korea Contents Association
• /
• v.9 no.12
• /
• pp.173-180
• /
• 2009

Increased appetite for art and design due to improving the economic standard of living and industrial community recognized the value of art in the profitable aspect currently demands various exhibitions in various environments. These social needs and changes in corporate culture to meet the rapidly expanding opportunities for artistic exhibitions, and this modern exhibition outside of the conventional gallery requires more for designers to work with various exhibition spaces, and the opportunities are increasing further. Various types of exhibition space in the exhibition planning an unspecified environment best suited to each exhibit space has been designed to require. This comprehensive study of an environmental poster exhibition held in the Seoul Institute of the Arts, MA-block lobby during 2009.06.10-06.19 was a part of the international exchange projects between Seoul Institute of the Arts and California State University, Northridge. Planning and designing throughout the exhibition in an unspecified space for exhibition requires more creativity and flexible approaches than in the general exhibition gallery.

• Korean Journal of Remote Sensing
• /
• v.30 no.6
• /
• pp.755-767
• /
• 2014

In this study, detailed air flow characteristics in an urban areas were analyzed using GIS data and a Computational Fluid Dynamics (CFD) model. For this, a building construction algorithm optimized for Geographic Information System (GIS) data with a vector format (Los Angeles region imagery acquisition consortium 2 geographic information system, LARIAC2 GIS) was used. In the LARIAC2 GIS data, building vertices were expressed as latitude and longitude. Using the model buildings constructed by the algorithm as the surface boundary data in the CFD model, we performed numerical simulations for two building-congested areas in Los Angeles using inflow information provided by California Air Resources Board. Comparing with the inflow, there was a marked difference in wind speed and direction within the target areas, which was mainly caused by the secondarily induced local circulations such as street-canyon vortices, horse-shoe vortices, and recirculation zones. In street canyons parallel to the inflow direction, wind speed increased due to a channeling effect and, in street canyons perpendicular to the inflow direction, vertically well developed vortices were induced. In front of a building, a horse-shoe vortex was developed near the surface and, behind a building, a recirculation zone was developed. Near the surface in the areas where the secondarily induced local circulations, wind speed remarkably increased. Overall, wind direction little (largely) changed at the areas where wind speed largely increased (decreased).

• Journal of Korean Society of Steel Construction
• /
• v.19 no.6
• /
• pp.587-597
• /
• 2007

Steel restrainer cables for multiple frame bridges in California in the United States have been shown to be effective in preventing unseating at internal hinges during the past several earthquakes. Consequently, the steel-cable-restrainer is being tested for applications on multiple-span-simply-supported (MSSS) bridges in the mid-American region. In addition, shape memory alloy (SMA) bars in tension are being studied for the same application, multiple frame bridges, the developed seismic forces are transferred to piers through the restrainers. However, in MSSS bridges, the seismic forces are transferred to abutments by the restrainers. Therefore, the abutment' behavior should also be investigated. In this study, we assessed the seismic performance of the three types of restrainers, such as steel restrainer cables, SMA in tension, and SMA in bending for an MSSS bridge from moderate to strong ground motion, bending test of an SMA bar was conducted and its analytical model was determined for this study. Nonlinear time history analyses were conducted to assess the seismic responses of the as-built and the retrofitted bridges. All three types of restrainers reduced the hinge opening and the SMA in tension was the most effective of the three devices in preventing the unseating, all restrainers produced damage on the abutment from the pulling action of the MSSS bridge due to strong ground motions, was found that the retrofit of the abutment in the pulling action is required in the installation of restrainers in MSSS bridges.

• The Journal of the Korea Contents Association
• /
• v.11 no.7
• /
• pp.168-178
• /
• 2011

Experiencing the vortex of postmodernism, modern graphic design has evolved radically from simple aesthetically-motivated style following modernism. Concurrently, Typography has transmuted into International Typography Style from Grid Standard, which was an outcome of modernism. Edward Fella is one of the most internationally prestigious figures practicing the contemporary graphic design style. He is currently pursuing his career as an educator by teaching graphic design and typography at Cal Arts. For a long time, Fella has devoted himself to yielding products of de-constructive presentations and constructing design identity based on aesthetics. This paper looks into aesthetic criteria which has affected modern graphic design, referring to graphism of Fella, an international graphic design and typography educator whose theoretical origins lie in French modern philosophy and aesthetics. Fella has created graphic works by making use of graphic motives residing in the unconscious and the subconscious. Therefore, his graphic style is viewed and investigated as de-constructive aesthetics in the paper. Drifting around toward the end of postmodernism, the present day defines itself as the age free of formality approaching uncertain future; however, Fella's typography graphically guides us to understand comprehensively not only how international graphic design flows from the present to the future, but its realizations in design works.