• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.5
• /
• pp.163-181
• /
• 2023

Improving the detection performance of facilities corresponding to the sensors of autonomous vehicles helps driving safety. In the road and transportation field, research is being conducted to improve the detection performance of sensors by road infrastructure or facilities. As part of this on the development of autonomous driving support infrastructure, the shape of traffic cones and drums to ensure sufficient LiDAR detection performance even rainy conditions and maintain the line-of-sight guidance function in construction zones improvement effect. The principle was to increase reflection performance and ensure no significant difference in shape from existing facilities. Traffic cones were manufactured in square pyramid shapes instead of cones, and drums were manufactured in hexagonal and octagonal pillar shapes instead of cylinders. LiDAR detection data for the facility was confirmed on a clear day and with 20 mm/h and 40 mm/h rainfall. The detection performance of the square pyramid-shaped traffic cone and octagonal column-shaped drum was to the existing facility. On the other hand, deviations occurred due to repeated measurements, and significance could not be confirmed through statistical analysis. By reflecting these results, future studies will seek a form in which data can be obtained uniformly despite the diversity of measurement environments.

• The Korean Journal of Mycology
• /
• v.51 no.4
• /
• pp.429-440
• /
• 2023

Wild Lentinula edodes (shiitake) strains are an important breeding material for developing new varieties suitable for various consumer preferences and environmental conditions. The morphological characteristics of 100 wild shiitake strains collected from 14 regions were investigated in a sawdust block cultivation. The characteristics of their fruiting bodies were diverse. Among them, 38% of the caps was convex, 33% was broadly umbonate, 27% was applanate, and 2% was shallowly depressed. In terms of their stipes, 55, 23, and 22% were the column, clavate, and funnel type, respectively. The shape of the cap was the most diverse on Mt. Hwaak, whereas the shape of the stipe showed various phenotypes from various regions. Even among strains collected from the same forest, different types of mushrooms were observed. In conclusion, wild shiitake strains that have adapted to various environmental stress can be used to develop new varieties. Thus, securing various genetic resources and studying their traits are important for researching breeding technology.

• Journal of Korean Society of Forest Science
• /
• v.31 no.1
• /
• pp.53-61
• /
• 1976

Though it is not easy for those who study dendrology to memorize all the scientific names of trees, the names remaines in their memory can facilitate the understanding of foreign technical books. The scientific name of a tree indicates characteristics of shape, color, and other aspects of the tree and by analyzing the name we can see common element found in other scientific names of trees. It is helpful to those who want to memorize and study the scientific names of trees if they understand their etymology. The preseut study is the seconds report of the investigation which aims at examining the etymology of the scientific names of native and foreign trees growing in Korea and their original names not only at the habitat but in Japan, China, England, Germany, and France. While the first report, which was made known in Theses Vol. 9. (The City College of Seoul 1975), is the examination of the scientific names of trees belonging to Gymnospermae, the present report is that of scientific names of trees belonging to Piperales: 2 families, 2 genera and 2 species; and trees belonging to Salicales: 1 family, 3 genera, 44 species, 16 varieties, and 3 forms. As the etymology of the scientific names of trees is made clear, this study will help those who want memorize the scientific names and study foreign technical books and it is also useful for international interchange of trees. The classification is depended chiefly on Dendrology by Prof. Lee Tchang-bok and "Plant Resources of Korea" shown in Biblography No. 10; the native names of trees on Jumoku Daizusetsu by Dr. Uehara; and etymology on A source-Book of Biological Names and Terms by E.C. Jager. In the column of etymology of the scientific names for genera, species, varieties and forms, Gr. stands for Greek, L. for Latin, NL. for New Latin, and genit. for genitive.

• Journal of Korean Society of Steel Construction
• /
• v.24 no.5
• /
• pp.511-520
• /
• 2012

The double split Tee connection, a type of full strength-partially restrained connection, has adequate flexural strength according to the changes in the thickness of the T-stub flange and the gauge distance of the high-strength bolts. Moreover, the double split Tee connection is designed and constructed with seismic connections that have enough ductility capacity applicable to ordinary moment frame and special moment frame by grade of steel, size of beam and column and geometric connection shape. However, such a domestic research and a proposal of a suitable design formula about the double split Tee connection are insufficient. Thus, many experimental and analytical studies are in need for the domestic application of the double split Tee connection. Therefore, this study aimed to examine and suggest feasibility of a design formula of the double split Tee connection of FEMA.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.23 no.4
• /
• pp.387-394
• /
• 2010

The alternative load path method based on a column removal scenario has been commonly used to protect building structures from being progressively collapsed due to probable blast loading. However, this method yields highly conservative result when the columns still have substantial load resisting capacity after blast. In this study, the behavior of RC columns with rectangular and circular sections under the blast loading was investigated and the remaining capacity of the partially damaged columns was compared. AUTODYN which is a hydrocode for the analysis of the structure on the impact and blast loading was used for this study. The blast loading was verified with the experiment results. The analysis results showed that the circular columns are preferable to the rectangular ones in respect of the blast resistance performance.

• Journal of architectural history
• /
• v.10 no.3 s.27
• /
• pp.45-60
• /
• 2001

The Tongdo temple have been transformed continuously since its first establishment about 1300 years ago. Nevertheless three critical elements specified by 'Jajangyulsa', founder of the temple have not varied over the times but rather strengthened and strongly combined. All elements and doctrines of the religion coexist and form a harmony within the whole of the temple. This researcher examined what changes, or combinations, in spatial formation were sought for such unique structures of the Tongue temple by focusing mainly on the Sangrojun area of the temple to obtain the following findings. First. unlike a work by a Japanese researcher 'Sekino Tadashi', the east yard of the main building was found located on the section line which corresponded to the separation line of Yungkuncheokdo(營建尺度=measure running) from the edge of the Keumkangkyedan(金剛戒壇 =Buddhist platform) embankment to the corner column of the Kamrodang. This was confirmed as a result of the review of photos shown in [Chosun Kojukdobo]. Second, the number of stairs used for the Keumkangkyedan was thought to become three when the temple was firstly restored in 1379 as a result that this researcher reviewed Chinese literature 'DoSun' and [Kyedandokyung(戒壇圖經)], records by 'Lee saek' and 'Jung Shihan', studies of Yungkun measure and actual changes in the temple. Then the temple was forth restored in 1705 when the second of the stairs was changed in area and height and at the same time grounded hard for a space for a Buddhist service. Third, the roof of the main building was probably changed in shape during the Koryo period when the plane structure, furnish arrangement, emphasized front, stone lanterns of the building and political factors of that time were all considered. Fourth, the main building was Initially designed to provide a Buddhist sermon service which was assumedly followed by a similar service at a Keumkangkyedan. Thus the main building had a small window on the northern side which might be opened up to look out or otherwise go outside like a door. However, the window was probably locked up like a surrounding wall since the main building was entirely repaired after the end of Japanese invasion of Korea in 1592.

• Steel and Composite Structures
• /
• v.23 no.5
• /
• pp.571-583
• /
• 2017

A kind of accordion-web RBS connection, "Tubular Web RBS (TW-RBS)" connection is proposed in this research. TW-RBS is made by replacing a part of web with a tube at the desirable location of the beam plastic hinge. This paper presents first a numerical study under cyclic load using ABAQUS finite element software. A test specimen is used for calibration and comparison of numerical results. Obtained results indicated that TW-RBS would reduce contribution of the beam web to the whole moment strength and creates a ductile fuse far from components of the beam-to-column connection. Besides, TW-RBS connection can increase story drift capacity up to 9% in the case of shallow beams which is much more than those stipulated by the current seismic codes. Furthermore, the tubular web like corrugated sheet can improve both the out-of-plane stiffness of the beam longitudinal axis and the flange stability condition due to the smaller width to thickness ratio of the beam flange in the plastic hinge region. Thus, the tubular web in the plastic hinge region improves lateral-torsional buckling stability of the beam as just local buckling of the beam flange at the center of the reduced section was observed during the tests. Also change of direction of strain in arc shape of the tubular web section is smaller than the accordion webs with sharp corners therefore the tubular web provides a better condition in terms of low-cycle fatigue than other accordion web with sharp corners.

• Journal of the Korean housing association
• /
• v.25 no.6
• /
• pp.111-121
• /
• 2014

The purpose of the study is to understand the unique characteristics of decoration style in traditional Javanese houses. Reviewing literature and visiting site were applied as the research method. Javanese House can be divided into three parts; roof, wall and floor. First, the roof of the traditional Javanese House is the most unique and important decorative element. The roofs are covered with roof-tiles and have clay carving ornaments on top. Usually there are no ceilings, just exposed to the oblique shape roof, which are made of wood to enable air ventilation. Joglo roof is the outstanding and representative roof type of Javanese houses. There is artistic and constructive roof structure named as tumpang sari in Joglo roof. The decoration on tumpang sari is the most colorful and symbolic ornaments. Secondly, the most unique element in the wall is the gebyok. Gebyok is made of wood and full of carved ornament, which has an artistic appearance, and also important function. The top part of doors are designed as perforated woodcarving, which give both aesthetic and ventilation purposes. Last, the stratified floor is begin with ground yard, then veranda that made from hardened clay, and main room constituted with a wood scaffold to provide air circulation and remove the humidity of the ground. The decorations of the column stand (umpak) are unique, where usually lotus flower is carved into black stone or lime stone. The outside of the buildings in Java Houses is not decorated by colors or symbols, whereas colors are only used in temples, pavilion or in royal housings. Instead they have carvings and decorations on important structural elements such as columns and beams inside. The ornaments and colors of decorations symbolize their god, ancestors and piece.

• Journal of Korean Society of Steel Construction
• /
• v.26 no.6
• /
• pp.499-509
• /
• 2014

This study focuses on mixing steel fiber in the concrete to improve the ductility and toughness of the columns. The purpose of the study is to evaluate the load capacity and deformation capacity associated with the amount of steel fiber and loading condition and to analyze the interplay between the steel fiber reinforced concrete and the welding built-up square tube in terms of structure and fire resistance performance. Reinforcement of concrete with steel fiber(Vf=0.375%), when cross-section shape and boundary condition (load ratio) remained unchanged, improved fire resistance performance by 1.1~1.3 times. It is deemed that the area resisting thermal load increased and fire resistance performance was improved since the concrete reinforced with steel fiber restrained cracking. In addition, the fact that the cross-sections of the concrete were barely damaged indicates that load share capacity was greatly improved.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2006.05a
• /
• pp.135-140
• /
• 2006

In the experimental study of $N_2$ purge cold flow test of impinging(FOOF) injector for determining of instability region, the whistling sound which has a specific frequency is generated. The frequency of whistling is proportional to the gas flow velocity in part of the oxidizer orifice and due to the coupling of the vibrating gas column and the natural frequency of pipe-orifice shape, the discontinuous jumping phenomena arises. The whistling phenomena have no effect on the combustion instability. Compared the damping factor of 1T1L mode with the hot fire test, the instability region of $N_2$ purge cold flow test is very much like that. It means that flow instability by impinging or mixing of jet is the main reason of combustion instability of impinging injector(FOOF) in the hot firing test.