• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.89-98
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• 2008

In this study, the behaviour of an unsaturated soil was analyzed by performing $K_0$ consolidated triaxial tests. Unsaturated triaxial tests were performed with matric suctions for weathered soils and stress paths under consolidation and stress-strain relationships under shear were obtained. As a result, the $K_0$ value decreased as the matric suction increased. Besides, both isotropic and $K_0$ conditions had similar shear strength envelopes at the same matric suction. Especially, strength parameters could be obtained by stress variables used in the critical state theory more reasonably than by those of Mohr circles at failure.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.532-536
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• 2015

This paper presents an automated computer vision-based system to update BIM data by leveraging multi-modal visual data collected from existing buildings under inspection. Currently, visual inspections are conducted for building envelopes or mechanical systems, and auditors analyze energy-related contextual information to examine if their performance is maintained as expected by the design. By translating 3D surface thermal profiles into energy performance metrics such as actual R-values at point-level and by mapping such properties to the associated BIM elements using XML Document Object Model (DOM), the proposed method shortens the energy performance modeling gap between the architectural information in the as-designed BIM and the as-is building condition, which improve the reliability of building energy analysis. The experimental results on existing buildings show that (1) the point-level thermography-based thermal resistance measurement can be automatically matched with the associated BIM elements; and (2) their corresponding thermal properties are automatically updated in gbXML schema. This paper provides practitioners with insight to uncover the fundamentals of how multi-modal visual data can be used to improve the accuracy of building energy modeling for retrofit analysis. Open research challenges and lessons learned from real-world case studies are discussed in detail.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.3
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• pp.289-294
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• 2023

As technologies such as cameras, Laser Imaging, Detection, and Ranging (LiDAR), and Global Navigation Satellite Systems (GNSS) become more sophisticated and common, their use in autonomous driving technologies is being explored in various fields. In the maritime area, technologies related to collision avoidance between ships are being developed to evaluate and avoid the risk of collision between ships by setting various scenarios. However, the position of each vessel used in the process of developing collision avoidance technology between vessels uses data obtained through GNSS, and may include a position error of 10 m or more depending on the situation. In this paper, a study on the dynamic safety navigation range including the positional inaccuracy of the ship is conducted. By combining the concept of the protection level obtained using GNSS raw data with a conventional safe navigation range, a safer navigation range can be calculated for dynamic navigation. The calculated range is verified using data obtained while sailing in an actual sea environment.

• Applied Microscopy
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• v.52
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• pp.6.1-6.5
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• 2022

We examined the morphology of the fertilized egg and the fine structure of fertilized egg envelopes of Poropanchax normani belonging to the family Poeciliidae, also known as Norman's lampeye using light and electron microscopes. The fertilized eggs with narrow perivitelline space were found to be spherical and demersal, additionally containing small oil droplets in the vitelline membrane. Further, a bundle of adhesive filaments was observed to be present on one side of the fertilized egg. These filaments possessed remarkably high elasticity and were approximately 1-3mm in length. The size of the fertilized egg was determined to be about 1.49 ± 0.07mm (n=30). The outer surface appeared smooth, and adhesive filaments originating at different location of the surface of the envelope were found to be distributed around the egg envelope and were joined together to form a single long bundle in scanning electron microscopic observation. A peak-like structure formed of several straight wrinkles was observed around the micropyle. However, the complete structure of the micropyle could not be studied due to the depth at which it was located. Additionally, the total thickness of the egg envelope was ascertained to be approximately12.5-14.5㎛. The egg envelope consisted of two distinct layers, an outer electron dense layer and an inner lamellar layer, further consisting of 10 sublayers of varying thicknesses. Collectively, it was observed that the morphological characteristics of the fertilized egg, fine structures surrounding the micropyle, outer surface, adhesive structure consisting adhesive filaments, and sections of fertilized egg envelope displayed species specificity.

• Applied Microscopy
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• v.51
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• pp.3.1-3.6
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• 2021

We examined the morphology of fertilized egg and ultrastructures of fertilized egg envelopes of dwarf rainbowfish (Melanotaenia praecox) belong to Melanotaeniidae using light and electron microscopes. The fertilized eggs were spherical with adhesive filament, transparent, demersal, and had a narrow perivitelline space and small oil droplets. The size of fertilized egg was 1.02 ± 0.18 mm (n = 30), and there were two kinds of adhesive filament on the fertilized eggs. The long and thick (diameter 12.22 ± 0.52 ㎛, n = 20) adhesive filaments were only at the area of animal pole, and short and thin (diameter 1.99 ± 0.23 ㎛, n = 20) adhesive filaments were around the long filaments. A micropyle was conical shaped with adhesive filament and located near the animal pole of egg. The outer surface of fertilized egg was rough side. Also, the total thickness of the fertilized egg envelope was about 7.46 ± 0.41 ㎛ (n = 20), the fertilized egg envelope consisted of two layers, an inner lamellae layer and an outer layer with high electron-density. And the inner layer was 8 layers. Collectively, these morphological characteristics and adhesive property of fertilized egg with adhesive filaments, and ultrastructures of micropyle, outer surface, and section of fertilized egg envelope are showed species specificity.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.11
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• pp.574-580
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• 2015

Climatic zone in building code is an administrative district classification reflecting regional climatic characteristics. Use of Degree-Days is a fundamental method that can be used in various building design codes, analysis of building energy performance, and establishment of minimum thermal transmittance of building envelopes. Many foreign countries, such as the USA, the EU, Australia, Italy, India, China, etc., have already adapted climatic zone classification with degree-days, precipitation or amount of water vapor based on the characteristics of their own country's climate. In Korea, however, the minimum requirements for regional thermal transmittance are classified separately for the Jungbu area, Nambu area and Jeju Island with no definite criterion. In this study, degree-days of 255 Korean cities were used for climatic zone classification. Outdoor dry-bulb temperature data from the Korea Meteorological Administration for 1981~2010 was used to calculate degree-days. ArcGIS and the calculated degree-days were utilized to analyze and visualize climatic zone classification. As a result, depending on the distribution and distinctive differences in degree-days, four climatic zones were derived : 1) Central area, 2) Mountain area of Gyeonggi and Gangwon provinces, 3) Southern area, and 4) Jeju Island. The climatic zones were suggested per administrative district for easy public understanding and utilization.

• Journal of The Korean Astronomical Society
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• v.27 no.1
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• pp.81-102
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• 1994

We have decomposed the 11-cm radio continuum emission of the W51 complex into thermal and non-thermal components. The distribution of the thermal emission has been determined by analyzing HI, CO, and IRAS $60-{\mu}m$ data. We have found a good correlation between the 11-cm thermal continuum and the 60- 11m emissions, which is used to obtain the thermal and non-thermal 11-cm continuum maps of the W51 complex. Most of the thermal continuum is emanating from the compact H II regions and their low-density ionized envelopes in W51A and W51B. All the H II regions, except G49.1-0.4 in W51B, have associated molecular clumps. The thermal radio continuum fluxes of the compact H II regions are proportional to the CO fluxes of molecular clumps. This is consistent with the previous results that the total mass of stars in an H II region is proportional to the mass of the associated molecular clump. According to our result, there are three non-thermal continuum sources in W51: G49.4-0.4 in W51A, a weak source close to G49.2-0.3 in W51B, and the shell source W51C. The non-thermal flux of G49.5-0.4 at 11-cm is $\~28 Jy$, which is $\~25\%$ of its total 11-cm flux. The radio continuum spectrum between 0.15 and 300 GHz also suggests an excess emission over thermal free-free emission. We show that the excess emission can be described as a non-thermal emission with a spectral index ${\alpha}{\simeq}-1.0 (S_v{\propto}V^a)$ attenuated by thermal free-free absorptions at low-frequencies. The non-thermal source close to G49.2-0.3 is weak $(\~9 Jy)$. The nature of the source is not known and the reality of the non-thermal emission needs to be confirmed. The non~thermal shell source W51C has a 11-cm flux of $\~130Jy$ and a spectral index ${\alpha}{\simeq}-0.26$.

• Journal of the Korean GEO-environmental Society
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• v.7 no.3
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• pp.31-41
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• 2006

The scale effect of specimens on the shear behavior of joints is studied by performing direct shear tests on six different sizes in Granite. The peak and residual shear stress, shear displacement, shear stiffness, and dilation angle are measured with the different normal stress(0.29~2.65MPa) and roughness parameters. It is also shown that both the joint roughness coefficient(JRC) and the joint compression strength(JCS) reduce with increasing joint length. A series of shear tests show about 56~67% reduction in peak shear stress, and about 18~44% in residual shear stress, respectively as the contact area of joint increases from 12.25 to $361cm^2$. Also the variation of dilation angle is $27^{\circ}$ at normal stress of 0.29 MPa and $6^{\circ}$ at normal stress of 2.65 MPa, respectively. The envelopes considering scale effect for JRC are made for the peak shear strength of rock joint in comparison with the Barton's equation.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.42.2-43
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• 2015

Massive stars play a major role in the interstellar energy budget and the shaping of the galactic environment. The water molecule is thought to be a sensitive tracer of physical conditions and dynamics in star-forming regions because of its large abundance variations between hot and cold regions. Herschel/HIFI allows us to observe the multiple rotational transitions of H2O including the ground-state levels, and its isotopologues toward high-mass star-forming regions in different evolutionary stages. Photodissociation regions (PDRs) are also targeted to investigate the distribution of water and its chemistry. We present line profiles and maps of H2O using data from two guaranteed-time key programs "Water In Star-forming regions with Herschel" and "Herschel observations of EXtra-Ordinary Sources". We analyze the temperature and density structures using LTE and non-LTE methods. We also estimate turbulent and expansion velocities, and abundance of water in the inner and outer envelopes using the 1D radiative transfer code. Around high-mass protostars we find H2O abundances of ~10-8-10-9 for the outer envelope and ~10-4-10-5 for the inner envelope, and expansion and turbulent velocities range from 1.0 km s-1 to 2.0 km s-1. The abundances and kinematic parameters of the sources do not show clear trends with evolutionary indicators. The Herschel/HIFI mapping observations of H2O toward the Orion Bar PDR show that H2O emission peaks between the shielded dense gas and the radicals position, in agreement with the theoretical and the observational PDR structure. The derived H2O abundance is ~10-7 and peaks at the depth of AV ~8 mag from the ionization front. Together with the low ortho-to-para ratio of H2O (~1) presented by Choi et al. (2014), our results show that the chemistry of water in the Orion Bar is dominated by photodesorption and photodissociation.