• Geophysics and Geophysical Exploration
• /
• v.17 no.2
• /
• pp.104-113
• /
• 2014

Electric resistivity monitoring was applied to evaluate the soft ground in reclaimed land in order to figure out the applicability of physical prospecting. For this, electrical resistivity monitoring data were acquired for total three months and analyzed those data with independent inversion, time-lapse inversion, and 4D inversion methods. The result was compared for various inversion methods so as to figure out what showed the soft soil most properly. Moreover, drilling and CPT(Cone Penetration Test) data were also used in order to find out if each of those inversion methods could distinguish either bed rock or the soft soil clearly. And according to the result, time-lapse inversion showed less inversion artifacts than independent inversion, so it could indicate the soft soil better. If data gained for a longer period than three months are used, 4D inversion has been found to be a more efficient analysis method than the time-lapse inversion method. Electrical resistivity monitoring on the soft soil has been found to be a useful method that can analyze the spatio-temporal electric state of the ground serially.

• Fire Science and Engineering
• /
• v.28 no.5
• /
• pp.71-79
• /
• 2014

This study was performed to test the combustive properties of Medium Density Fibreboards (MDFs) treated with chemicals of the bis-(dimethylaminomethyl) phosphinic acid (DMDAP), N,N-dimethylethylenediaminomethyl-bis-phosphonic acid (DMDEDAP), piperazinomethyl-bis-phosphonic acid (PIPEABP), and methylpiperazinomethyl-bis-phosphonic acid (MPIPEABP). MDFs were painted in three times with 15 wt% solution of the bis-(dimethylaminomethyl) phosphinic acid and alkylenediaminoalkyl-bis-phosphonic acids at the room temperature, respectively. After drying MDF treated with chemicals, combustive properties and volatile organic compounds (VOCs) contents were examined by the cone calorimeter (ISO 5660-1), test for flame retardant (NEMA Notice No. 2012034), and gas chromatography (KS M ISO 11890-2), respectively. It was indicated that the MDFs treated with chemicals showed the longer time to combustion time (CT) = (442~492) s than that of virgin plate by reducing the burning rate except for CT treated with DMDAP. In adition, the MDFs treated with chemicals showed both of the higher char area (44.33~61.33) kg/kg and char length (10.33~11.67) cm than those of virgin plate. Especially, the MDFs treated with chemicals showed the higher mean volatile organic compounds (VOCs) (0.188~0.333) g/L than that of virgin plate within the prescribed limits. Thus, It is supposed that the combustion- retardation properties were improved by the partial due to the treated chemicals in the virgin MDF.

• Fire Science and Engineering
• /
• v.27 no.4
• /
• pp.21-26
• /
• 2013

This study was performed to test the combustive properties of Pinus rigida plates treated with bis-(dimethylaminomethyl) phosphinic acid (DMDAP), bis-(diethylaminomethyl) phosphinic acid (DEDAP), and bis-(dibuthylaminomethyl) phosphinic acid (DBDAP). Pinus rigida specimens were painted in three times with 15 wt% bis-(dialkylaminoalkyl) phosphinic acid solutions at the room temperature. After drying specimen treated with chemicals, combustive properties were examined by the cone calorimeter (ISO 5660-1). It is supposed that the combustion-retardation properties were improved by the partial due to the treated bis-(dialkylaminoalkyl) phosphinic acids in the virgin Pinus rigida. Especially, the specimens treated with chemicals showed both the lower total smoke release rate (TSRR) ($16.94{\sim}18.92m^2/m^2$) and lower $CO_{2mean}$ production (1.98~2.09 kg/kg) than those of virgin plate. However the specimens treated with chemicals showed both the higher peak mass loss rate (PMLR) (0.1250~0.1297 g/s) and higher 1st-smoke production rate (SPR) (0.0153~0.0167 g/s) than those of virgin plate. Compared with virgin Pinus rigida plate, the specimens treated with the bis-dialkylamimoalkyl phosphinic acids showed partially low combustive properties.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.2
• /
• pp.90-96
• /
• 2009

The high rising building construction makes increasing the requirement of high strength concrete. Especially, the workability analysis is related with dispersion of admixture such as SF for improving strength and FA, BS for reducing construction cost and improving durability of Ultra High Strength Concrete which has over 100 MPa of compressive strength is very important. Precisely, decreases dispersion because of lumping situation of each admixture and it causes the workability of admixture is decreased. Therefore, the workability of cement paste is tested for analyze effects of pre-mixed cement for solving those problems with it to this research. The summary of the results are like below. First of all, OBS is increasing workability more than OFS. This result causes that the glassy surface of BS in the OBS is increasing workability and the absorption of admixture of FA in the OFS is decreasing workability. In the case of mixing methods, pre-mixing method is increasing workability more than normal one. This result shows that the normal mixing method is bad dispersion of binders. The other side, the pre-mixing method is good. Furthermore, depending on the mixing time, according to the increasing mixing time such as 30, 60, and 120 seconds, the dispersion of binders and workability turns better.

• Journal of the Korean GEO-environmental Society
• /
• v.8 no.1
• /
• pp.33-40
• /
• 2007

Engineering behaviour of uplift-resisting ground anchors constructed in weathered rocks has been investigated by carrying out a series of full scale pull-out tests. The anchor was to resist uplift forces (buoyancy) associated with high groundwater table acting on the basement of a rail way station. The study has included the ultimate pull-out capacity of the anchors and shear stress transfer mechanism at the anchor-ground interface. The pull-out tests were conducted by changing bonded lengths of the anchor (2~7 m) and diameter of drilled borehole (108~165 mm) to investigate their effects on the behaviour of the anchor. The measured results showed that the ultimate capacity of the anchors was increased with an increase in the bonded length, diameter of drilled borehole as expected. The ultimate capacity of the anchors deduced from the pull-out tests ranged from 392 to 1,569 kN, depending on the above-mentioned factors. This corresponds to the interface shear strength of about 227~505 kPa. Interface shear stresses deduced from the pull-out test showed that the larger the pull-out force, the larger the mobilisation of the interface shear strength. The failure mode of the anchors heavily depended on the bonded lengths of the anchors. When the bonded length was short (2~3 m), a cone-type failure was observed, whereas when the bonded length increased (5~7 m), failure developed at the grout-ground interface.

• Journal of Navigation and Port Research
• /
• v.35 no.5
• /
• pp.393-400
• /
• 2011

The residential complexes in waterfront provide the residents with pleasantness and comfort with their scenety and view in the surrounding watersides. However, it is currently true that there has little been established any designing plan utilizing the environmental characteristics of the waterfront. In this study, a survey was conducted on the residents of a Japanese waterfront. in Nishimiyahama and Lake Biwa, and conducted a comparative and analytic investigation regarding water-friendly activities, residents' consciousness of the housing environment, and reasons for the choice of residenve. From the results, we were able to obtain some suggestive points resulting from the differences of the aforementioned. We also fully comprehended that there are some issues and needs for solution for the environmental characteristics in the waterfront as well as for the damage incurred by salt breeze and insects. In addition, we realized that scenery and view toward watersides are becoming the important factors in the residents' consciousness regarding the housing environment. In case of planning housing complexes located in the waterfront, we keenly understood that "the size of a room", "ventilation", "view and daily lighting", and "securing privacy" are having effects on the residents' consciousness of their housing.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2009.10a
• /
• pp.136-137
• /
• 2009

Japanese waterfront project consisted actively from an early stage in 1980's, and the project which activated an area in a destination in a various part of Japan was implemented. For a study to however conscious whether the user in water front be of the waterside space in such waterfront project paper its number is very small. A questionnaire survey was put into effect targeted for 17 points of Japanese typical waterfront project paper completed in about 1990 by this research. With the foundation of this, a member item mean, it was possible to classify development paper of 17 results factor analysis is by 4 kind type of the aquarium type, the natural type, the middle type and the artificial type. And it was possible to classify the motive item conscious of the waterside space by 7 kinds, a view, smell, hearing, sense of touch, the taste, existence of facilities and activity behavior. When seeing the motive item in the center, sight was highest by 57% and about 8%, sense of touch, hearing and olfactory three senses had the lowest taste by 1%. "With aquarium" existence of facilities including etc was about 12 %, and activity behavior including Hitoshi who" can clear a quay" was about 6 %, and it appeared.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.17 no.5
• /
• pp.31-39
• /
• 2013

In this study, performance of the post-installed anchor system was evaluated with reduced strength of concrete and anchor. One of the post-installed anchors was selected to performance evaluation. Concrete strength was reduced by freeze-thawing test, and the post-installed anchor strength was reduced by corrosion test. The post-installed Anchor was installed in concrete of freezing and thawing and original concrete, and corroded anchor was installed in original concrete only. Anchor diameter and installation depth of the anchor were the variable for each specimen. Performance of post-installed anchor system of each specimen was evaluated by pullout test. Anchor diameter and installation depth of anchor, it may affect the performance of the post-installed anchor system from the experimental test results. Fracture mode of each post-installed anchor system had occurred differently depending on the durability of concrete and anchor. The anchor pullout strength from the experimental test results was used in order to compare with the results of CCD (Concrete Capacity Design) method, and CCD equation was modified. Modified equation was able to predict the anchor pullout strength of post-installed anchor system in Original concrete and freezing and thawing of concrete.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.10a
• /
• pp.37-38
• /
• 2012

This study intended for Yokohama Minato Mirai21 district in Japan as waterfront, and Korea did an object again in Haeundae on high ground beach, a Jagalchi market. I carried out questionary survey in an object with the three places and investigated human waterside space consciousness to keep that I came and went. I analyzed the waterside space consciousness of the user to see a questionnaire result. It was 78.7% of 237 people, and there was much 'which felt the' sea breeze for the waterside space consciousness most, and 'that' which the 'sea was seen next saw 217 72.1%,' ship appeared by 203 67.4% order. I carried out reclassification for human five senses (sight, hearing, the sense of touch, taste, sense of smell) and activity, seven items such as the existence of the institution by the question contents of 19 about the waterside space consciousness each and grasped the consciousness of the waterfront user. As a result, Haeundae sense of smell was 32.3%, and a Jagalchi market was that sense of smell (26.1%) had an influence on the waterside space consciousness in 32.3% of taste, 21, Minato Mirai, Yokohama district, and sea building on high ground beach appeared.

• The KIPS Transactions:PartA
• /
• v.8A no.4
• /
• pp.479-488
• /
• 2001

As the SoC designs complexity constantly increases, the simulation that uses their software models simply takes too much time. To solve this problem, FPGA-based logic emulators have been developed and commonly used in the industry. However, FPGA-based logic emulators are facing with the problems of which not only very low FPGA resource usage rate due to the very limited number of pins in FPGAs, but also the emulation speed getting slow drastically as the complexity of designs increases. In this paper, we proposed a new innovative emulation architecture and its software that has high FPGA resource usage rate and makes the emulation extremely fast. The proposed emulation system has merits to overcome the FPGA pin limitation by pipelined ring which transfers multiple logic signal through a single physical pin, and it also makes possible to use a high speed system clock through the intelligent ring topology. In this topology, not only all signal transfer channels among EPGAs are totally separated from user logic so that a high speed system clock can be used, but also the depth of combinational paths is kept swallow as much as possible. Both of these are contributed to achieve high speed emulation. For pipelined singnals transfer among FPGAs we adopt a few heuristic scheduling having low computation complexity. Experimental result with a 12 bit microcontroller has shown that high speed emulation possible even with these simple heuristic scheduling algorithms.