• Journal of the Korean GEO-environmental Society
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• v.18 no.9
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• pp.19-31
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• 2017

In case of USA, the drilled shaft and the driven pile in the field showed a good correlation in the analysis of the bearing capacity between the dynamic load test and the static load test. However, in Korea, we mainly install the bored pile, which is not widely used overseas and we tried to confirm the reliability of the dynamic load test on the bored pile, because many people questioned the reliability of it. In this study, load tests were carried out on PHC bored piles in LH field (Cheonan, Incheon, Uijeongbu), and the bearing capacity of the dynamic load test (EOID 7times, Restrike 7times) and the static load test (7times) were compared and analyzed. As a result, the average of the bearing capacity of the static load test was 27% higher than that of the dynamic load test (reliability : 0.73, coefficient of variation : 0.3). And the average of the bearing capacity of the static load test (Davisson) was 27% higher than that of the bearing capacity of the dynamic load test (Davisson) (reliability : 0.73, coefficient of variation : 0.2). To reduce the difference between the bearing capacity of the dynamic load test and the static load test, we proposed modified bearing capacity of dynamic load test (base bearing capacity of EOID + skin frictional force of restrike) and difference between the bearing capacities was reduced to 9% (reliability : 0.91, coefficient of variation : 0.2). And the coefficient of variation was reduced to 0.2 and the consistency of analysis increased.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.33-40
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• 2000

The horizontal drain method is one of the soil improvement methods in reclamation works using dredged soils. In this method, plastic drain boards are installed horizontally in the ground, and a seepage pressure or negative pressure is applied through one end of these drains. In this study, a basic consolidation test using horizontal drains was conducted to investigate the effectiveness of this method. The configuration of soil box which was used in this test is 100cm(B)${\times}$100cm(L)${\times}$85cm(H). The drain board was reduced to 25mm${\times}$5mm. The variations in settlement and volume of drain water during the consolidation process were measured, and the distribution of water content and the transpormation of horizontal drain were investigated.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.113-121
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• 2004

A test program was conducted on full-scale steel moment connections constructed using a T-stiffener. In the T-stiffener connection, the beam-to-column connection was reinforced with the horizontal and vertical element of the T-stiffener to resist moment under severe cyclic loads. A total of five specimens were tested in this study together with a concrete-filled tubular(CFT) column(${\sqsubset}-500{\times}500{\times}12$) and a steel beam($H-506{\times}201{\times}11{\times}19$). For the specimens, the T-stiffener was combined with RBS (also known as "Dog-bone") detail or Horizontal Element Hole(HEH) detail constructed to enhance deformation capacity. The test program showed excellent seismic performance for specimens constructed with an RBS or an HEH. except the specimens had brittle failure of VE. The test results also showed that the connections all developed maximum moments at the face of the column. Such moments were at least 15% and as much as 36% larger than the plastic moment capacity of the beam. based on the actual yield stress of the beam steel.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1240-1249
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• 2017

An essential component of the neutron transport solver is the resonance self-shielding calculation used to determine equivalence cross sections. The neutron transport code, MPACT, is currently using the subgroup self-shielding method, in which the method of characteristics (MOC) is used to solve purely absorbing fixed-source problems. Recent efforts incorporating multigroup kernels to the MOC solvers in MPACT have reduced runtime by roughly $2{\times}$. Applying the same concepts for self-shielding and developing a novel lumped parameter approach to MOC, substantial improvements have also been made to the self-shielding computational efficiency without sacrificing any accuracy. These new multigroup and lumped parameter capabilities have been demonstrated on two test cases: (1) a single lattice with quarter symmetry known as VERA (Virtual Environment for Reactor Applications) Progression Problem 2a and (2) a two-dimensional quarter-core slice known as Problem 5a-2D. From these cases, self-shielding computational time was reduced by roughly $3-4{\times}$, with a corresponding 15-20% increase in overall memory burden. An azimuthal angle sensitivity study also shows that only half as many angles are needed, yielding an additional speedup of $2{\times}$. In total, the improvements yield roughly a $7-8{\times}$ speedup. Given these performance benefits, these approaches have been adopted as the default in MPACT.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.2
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• pp.101-112
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• 2007

Purpose : The purpose of this study was to evaluate influence of sacroiliac joint mobilization on lower extremity muscle strength. Methods : The subjects were consisted of thirty patients who had Leg length inequality(LLI) of more than 10mm(16 females. 14 males) from 21 to 41 years of age(mean aged 24.87). All subjects randomly assigned to sacroiliac joint mobilization group(n=15), control group(n=15). sacroiliac joint mobilization group received sacroiliac joint mobilization about 10 minutes for 3 times per week during 4 weeks period. Control group not received intervention during 4 weeks period. The tape measure method(TMM) was used to measure functional Leg length inequality. Biodex System 3 Pro was used to measure strength of Knee extension & flexion. All measurements of each subjects were measured at pre-test, 2weeks post-test and 4weeks post-test. Results : 1. The LLI of sacroiliac joint mobilization group was significantly reduced according to within treatment period(p<.05), most significantly reduced between pre-test and post-test(p<.05). sacroiliac joint mobilization group significantly more reduced than control group(p<.05). 2. The knee extension strength of sacroiliac joint mobilization group was significantly increased according to within treatment period(p<.05), most significantly increased between pre-test and post-test(p<.05). sacroiliac joint mobilization group significantly more increased than control group(p<.05). 3. The knee flexion strength of sacroiliac joint mobilization group was significantly increased according to within treatment period(p<.05), most significantly increased between pre-test and post-test(p<.05). sacroiliac joint mobilization group significantly more increased than control group(p<.05). Conclusion : sacroiliac joint mobilization can reduce LLI and increased lower extremity muscle strength.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.2
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• pp.183-194
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• 2007

Purpose : The purpose of this study was to evaluate influence of therapeutic exercise on functional leg length inequality(LLI). Methods : The subjects were consisted of thirty patients who had Leg length inequality(LLI) of more than 10mm(l6 females. 14 males) from 20 to 35 years of age(mean aged 24.23). All subjects randomly assigned to contract-relax exercise of proprioceptive neuromuscular facilitation(PNF) group(n=15), control group(n=15). Contract-relax exercise group received contract-relax exercise about 10 minutes with therapeutic massage about 15 minutes for 3 times per week during 4 weeks period. Control group not received intervention during 4 weeks period. The tape measure method(TMM) was used to measure functional Leg length inequality. Biodex System 3 Pro was used to measure strength of Knee extension & flexion. All measurements of each subjects were measured at pre-test, 2weeks post-test and 4weeks post-test. Results : 1. The LLI of contract-relax exercise group was significantly reduced according to within treatment period(p<.05), most significantly reduced between pre-test and post-test(p<.05). Contract-relax exercise group significantly more reduced than control group(p<.05). 2. The knee extension strength of contract-relax exercise group was significantly increased according to within treatment period(p<.05), most significantly increased between pre-test and post-test(p<.05). Contract-relax exercise group significantly more increased than control group(p<.05). 3. The knee flexion strength of contract-relax exercise group was significantly increased according to within treatment period(p<.05), most significantly increased between pre-test and post-test(p<.05). Contract-relax exercise group significantly more increased than control group(p<.05). Conclusion : Contract-relax exercise applied with therapeutic massage can reduce LLI and increased lower extremity muscle strength.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.345-355
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• 2014

Today's System-on-a-Chip (SoC) is designed with reusable IP cores to meet short time-to-market requirements. However, the increasing cost of testing becomes a big burden in manufacturing a highly integrated SoC. In this paper, an efficient parallel scan test technique is introduced to minimize the test application time. Multiple scan enable signals are adopted to implement scan architecture to achieve optimal test application time for the test patterns scheduled for concurrent scan test. Experimental results show that testing times are considerably reduced with little area overhead.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.591-594
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• 2003

It is reported that the amount of reinforcements for domestic PSC box girder bridges is used two times more that those for foreign PSC box girder bridges, which is considered to be irrational and uneconomical. Therefore, we have come to the conclusion through this study that the advanced design direction can reduce the amount of reinforcements under the condition that the static load test and the nonlinear analysis for the specimen of the PSC box girder bridge with reduced reinforcements which is designed by advanced design direction was carried out in order to verify the validity of the advanced design direction.

• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.291-305
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• 2013

This paper presents the continuous hoop reinforcement method as a means to overcome the difficulty of rebar construction due to the seismic detail of lateral reinforcement. Because the continuous hoop has no seismic hook, and there is less interference during the rebar work, rebar quantities and construction time can be reduced. Since the details of column and beam continuous hoops are different from those of conventional lateral reinforcements, the construction method should be developed through mock-up tests. The length of the beam mock-up is 8m and the section size is $500mm{\times}700mm$, the height of the column mock-up is 2.8m and 4m, and the section size is $800{\times}800mm$. The length and the size are determined based on the elements that are generally used in reinforced concrete basement parking lots and office buildings. The results of the mock-up test showed that the quantities of rebar could be reduced by 20% and the time could be reduced by up to 40% compared with conventional lateral reinforcements.

• Journal of Environmental Science International
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• v.8 no.3
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• pp.363-369
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• 1999

This study aimed to elucidate the relationship between theoretical parameters affecting the coagulation process and the real coagulation phenomenon applied to the dye wastewater. Emphasis was placed on the effective removal of the suspend particulates. Parameters studied in this study are pH, coagulant concentration and surface potential. Optimal dosages of coagulants by the measurement of the zeta potential at lower then $25^{\circ}C$ are 5\times$10^P-3}$ M of $FeCl_3 and 1.4\times10^{-6}M of Fe_2(SO_4)_3$. The results were well agreeded with the separate Jar-test results. Emphasis was also placed on the relationship between water quality and the content of SS. It was found that the COD and DOC were reduced to 65% and 85%, respectively. The turbidity at the above condition was reduced from 300 NTU to 0~1 NTU. Efforts were made to clarify the behavior of the suspend solid as affecting the water quality. 12,000~13,000 particles/10mL in $1~50\mu$m size range particulates in the raw wastewater were reduced to 300 particle/10mL in the same range after treatment. This research has proposed the methodology to find out the optimal condition of coagulation for small scale wastewater treatment plant or chemical coagulation process.