• Journal of the Korean Geotechnical Society
• /
• v.35 no.12
• /
• pp.101-109
• /
• 2019

The bucket platform is a new structure suitable for construction of offshore bridge foundations and providing the temporary support for equipments and labour. The platform can be subjected to moment loading due to the eccentric loading or the horizontal load by wave and wind. Therefore, a three dimensional finite element analysis was performed to evaluate the moment bearing capacity of the bucket platform, varying soil density, the diameter and embedment depth of the bucket. The numerical modeling was verified and compared with the moment-rotation curve from a field loading test. The uniform sandy ground was assumed and the moment load was applied at the top plate of the platform, increasing bucket rotation. The moment-rotation relations were analyzed to determine the moment capacity, which was influenced by the embedment depth and diameter of the bucket. Finally, a preliminary design equation was suggested to estimate the moment bearing capacity.

• Korean Journal of Food Science and Technology
• /
• v.23 no.4
• /
• pp.420-427
• /
• 1991

The structure of fresh, salted and heated petiole tissue from Chinese cabbage was examined with optical microscope, and the pectin of the tissues was fractionated by successive extraction. The pectin in Chinese cabbage consisted mainly of high methoxyl pectin(pA) and low methoxyl pectin(pB). The pA content was converted to pB markedly by salting and heating at $60{\sim}70^{\circ}C$ for 30 min while heating the cabbage above 80 decreased pB content. The firmness of heated tissue was highly correlated with pB content(r=0.996). Cytorrhysis test showed that pore size of the tissue became smaller by salting and heating at temperature below $80^{\circ}C$.

• Journal of Advanced Navigation Technology
• /
• v.12 no.1
• /
• pp.34-45
• /
• 2008

Broadcast encryption schemes are applied to transmit digital informations of multimedia, software, Pay-TV etc. in public network. User acquires message or session key to use key that broadcaster transmits, broadcaster need process that generation and distribution key in these process. Also, user secession new when join efficient key renewal need. In this paper, introduce about efficient key generation and distribution, key renewal method. The temporary conference environment base structure against an each mobile device wild gap. Without the transmission possible, it follows infrequent location change and with the quality where the key information change flow. Thus, in this paper, in order to apply to the embedded computing environment and the key generation and the efficient key renewal are done when the mobile device is used of the specify space it proposes.

• The KIPS Transactions:PartD
• /
• v.18D no.1
• /
• pp.1-8
• /
• 2011

The cache structure, which is designed for assuring fast accesses to frequently accessed data, resides on the various levels of computer system hierarchies. Many studies on this cache structure have been conducted and thus many page-replacement algorithms have been proposed. Most of page-replacement algorithms are designed on the basis of heuristic methods by using their own criteria such as how recently pages are accessed and how often they are accessed. This data-retrieval process in computer systems is analogous to human memory retrieval process since the retrieval process of human memory depends on frequency and recency of the retrieval events as well. A recent study regarding human memory cognition revealed that the possibility of the retrieval success and the retrieval latency have a strong correlation with the frequency and recency of the previous retrieval events. In this paper, we propose a novel page-replacement algorithm by utilizing the knowledge from the recent research regarding human memory cognition. Through a set of experiments, we demonstrated that our new method presents better hit-ratio than the LRFU algorithm which has been known as the best performing page-replacement algorithm for DBMS caches.

• Spatial Information Research
• /
• v.21 no.1
• /
• pp.37-44
• /
• 2013

This study sets the boundary of U-City industry based on expert surveys. Based on this U-City industry boundary, an appropriate inter-industry analysis is performed. The result shows production inducement coefficients, value added inducement coefficients, employment & enter employment inducement coefficients, influence coefficients and induction coefficients. Based on these coefficients, overall characteristics and spillover effects of U-City industry are examined. The result of this study shows that U-City industry has bigger value added-induced effects and employee-induced effects than other industry. The result also shows that U-City industry also has a great forward linkage effect. This study has a meaning that could be used to make political decisions as a basic data.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.16 no.2
• /
• pp.75-82
• /
• 1987

This study was to investigate physicochemical and microbial changes that took place during the salting of chinese cabbages. Salinity(3%) that is suitable for kimchi preparation was reached when chinese cabbages were salted for seven hours in 10%, three hours in 15% and one hour in 20%. In the case of 5% it was not reached though they were salted for over twelve hours. In order to decrease salinity from 7% level of salted chinese cabbages to 3% level by soaking in tap water, 1.2 hours for leaf and three hours for patiole were spent. Volume, moisture, firmness and internal space of raw chinese cabbages were significantly decreased by salting (15%, 10 hours) : volume, 59.90%, moisture, about 31.92% and internal space rate, 35.06%. Contents of mono-and divalent cations$(K^+,\;Mg^{2+}\;and\;Ca^{2+})$ were reduced whereas $Na^+$ content was greatly increased; therefore, in the future the increase of Na-content remains open to question. By salting and washing, mold, yeast and bacteria were decreased by 58%, 40%, 45%, respectivity.

• Journal of Advanced Navigation Technology
• /
• v.18 no.6
• /
• pp.546-554
• /
• 2014

For improvement of network RTK performance in survey field, Spatial Information Research Institute (SIRI), LX Korea Cadastral Survey Corporation installed 30 GNSS permanent stations in Korea Peninsula, and has been running the MAC-based network RTK service as a test version. In this paper, we introduce the LX GNSS network and analyze the positioning accuracy of the LX MAC RTK service. For field test of the LX MAC RTK service, we installed temporally fixed anchor points and observed simultaneously with VRS of National Geographic Information Institute. As a result, the horizontal position differences and initial times of LX MAC with respect to NGII VRS are $1{\sim}2{\pm}1cm$ and <10 seconds, respectively.

• Tunnel and Underground Space
• /
• v.27 no.4
• /
• pp.195-204
• /
• 2017

This case study introduces the construction of large cross section tunnel for underground ventilation system in Sillim-Bongcheon Tunnel Project. In order to grant the safety and efficiency in connecting the ventilation shaft (7.8 m of width, and 6.6 m of height) to a tunnel for axial fan facility (20.8 m of width, and 12.3 m of height), gradual enlargement of tunnel cross section was employed between those and temporary support method was determined based on Q system. In addition, some original designs were revised during construction stage to improve the efficiency of excavation in large cross section tunnel. The advance length was optimized and top heading of the tunnel was excavated without partition in accordance with ground condition and numerical stability analysis results. It is believed that some experiences and considerations in this case study will be useful for the future design and construction in similar large cross section tunnel such as large underground ventilation system or road tunnel with four lanes.

• Tunnel and Underground Space
• /
• v.15 no.5 s.58
• /
• pp.359-368
• /
• 2005

In case the overburden of a tunnel is too low to adopt NATM, cut and cover method generally can be chosen as alternative. However, in tunneling some area with very low or no overburden between two mountains, the cut and cover method requires additional construction of a couple of tunnel portals and the maintenance of portal slopes until backfilling is completed. As a solution for this problem, increasing the tunnel overburden by raising the ground level can be effective. This paper presents the case study for tunneling at C240 site in Taiwan High Speed Railway(THSR) in which soil-cement filling method was used for pre-banking before tunnel excavation. Cement content of filling material was $2\~4\%$ and thickness of filling a round was $130\~250\;mm$. The stability evaluation for the soil-cement slope and concrete lining of low cover tunnel was conducted by numerical analysis.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.5
• /
• pp.77-84
• /
• 2011

Korea and some other countries located in the northern hemisphere employ the air conditioner for the space cooling in the hot summer season and also some kinds of heaters for the space heating in the cold winter season. Especially in Korea, a great number of air conditioners of about 12,700,000 sets have been used these days. However, they are used for a short operation period of only 58 days a year, which results in the material and economic losses. To solve this problem and employ this system for the emergency shelter, a new conversion unit which could convert the existing air conditioner to a heat pump system for simultaneous heating and cooling was developed in this study, and the thermal performance was tested. The results indicated that the indoor air could be heated from $27^{\circ}C$ to $39^{\circ}C$ by the air conditioner converted to a heat pump system with the ambient temperature variation of $-10^{\circ}C{\sim}10^{\circ}C$, and cooled from $20^{\circ}C$ to $15^{\circ}C$ by the converted system with the ambient temperature variation of $20^{\circ}C{\sim}35^{\circ}C$. And also the heating COP increased from 3.3 to 5.3 in case of the heat exchange of the super cooling(HESC) circuit and from 3.0 to 4.0 in case of the By-pass with the ambient temperature variation of $-10^{\circ}C{\sim}10^{\circ}C$, respectively, whereas the cooling COP decreased from 3.1 to 2.1with the increase of the ambient temperature from $20^{\circ}C$ to $35^{\circ}C$.