• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.917-917
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• 2003

The auditory experiments based on the subjective annoyance responses were undertaken for the establishment of the adverb modifiers of the heavy-weight impact noises. The standard heavy weight impact noise, impact ball noise and adult walking noise were recorded by dummy head at a newly-built apartment and were presented to the subjects by headphones. The levels of the three impact noises were varied from 30 to 60㏈(A) and the subjects matched one of the adverb modifiers to each level of the noise sources. As a result, seven scale modifiers were established and the intervals between the modifiers were found as equal. In addition, it was found that the lower annoyance noise limits for the heavyweight impact, impact ball and walking were 40-45㏈ (L$\sub$I, Fmax. AW), which is 6㏈ lower than in the previous study. The background noise level was as low as 21㏈(A) in the test booth, therefore, the testing conditions need to be concerned for evaluation of floor impact noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.197-202
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• 2014

Floor Impact Noise is a structure-borne noise which is mainly caused by vibration of concrete slabs. The majority of previous studies have focused on investigating performance of absorbing sheets on the reduction of floor impact noise. But absorbing sheets do not efficiently reduce heavy-weight floor impact noise level because it cannot absorb slab vibration, which is the fundamental noise source. In this study, double-floor system was developed in order to reduce floor impact noise level in residual buildings. This floor system reduces heavy-weight impact noise level by reducing vibration response at the center of slab, which has maximum amplitude in the 1st vibration mode. In order to identify the performance of the double-floor system, experiments were planned. Primary test parameters are span of double floor, arrangement and types of absorbing sheets.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.2
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• pp.162-168
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• 2009

In this study, numerical analysis is performed to investigate the sound radiation characteristics of an apartment house according to the type of the slab system. In order to satisfy the boundary condition of the apartment house, the whole floor is modelled with FEM model for three different structural system: wall, RC, flat slab system. From the analytical results, it is shown that heavy weight floor impact noise of wall type slab is larger than that of the other slab systems and the noise radiated from the wall have great effect on the sound pressure level. The results also show that the vibration energy of RC or flat slab system is widely distributed over the whole slab, which is main reason that the noise induced by the slab systems is reduced in comparison with wall slab system.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.491-495
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• 2014

Phytoremediation is a technology using plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments. It is regarded as a cost-effective, efficient, eco-friendly, and solar-driven technology with good public acceptance. This study was conducted to find the plants accumulating heavy metals in soils contaminated with Cd and Pb. Experimental plots (plot size: $0.81m^2$) was artificially contaminated using a contaminated soil collected from a field in vicinity of Wondong mine (WD). Sunflower, corn and castor were tested for their potential to remove heavy metals from the contaminated soils. The results indicated that sunflower was most effective in accumulating heavy metals and thus remedying the soils among the three crops. Dry weight and heavy metal uptake of sunflower shoot differed with growth period. For example, the Cd content of shoots including leaf and stem were 0.31mg, 2.23 mg, and 0.96 mg per plot at 4, 8 and 12 weeks after planting in Cd4-WD treatment; in addition, the dry weight of the shoots in Cd8-WD treatment was reduced due to heavy metal toxicity. This experiment showed that sunflower absorbed Cd, Pb and Zn in their shoots up to 8 weeks of planting; thereafter heavy metals uptake was diminished. This implies that the efficiency of these plants in cleaning the contaminated soils may be high at the early stage of plant growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.3
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• pp.270-276
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• 2010

This study estimated the heavy metal concentrations in octopus (Octopus minor) and conducted a food safety assessment of octopus. Octopus, a benthic cephalopod, was collected from the Seosan intertidal zone on the west coast of Korea. The samples were digested with acids, and then the cadmium (Cd), copper (Cu), and zinc (Zn) contents were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The Cd, Cu, and Zn range of concentrations in octopus were 0.06-19 (mean 5.8), 44-1,463 (mean 354.8), and 76-929 (mean 247.9) mg/kg on a dry weight basis, respectively. The concentrations of heavy metals were higher in the internal organs than in the mantle. Of the three heavy metals, copper had the highest concentrations in the internal organs because of the existence of hemocyanin bound with copper in octopus blood, whereas zinc had the highest concentrations in the mantle. No relationship between the concentration of heavy metals and biological parameters (length, weight, and sex) was found. The ratios (I/M) of the heavy metal concentrations in internal organs and mantle were highest for cadmium, although cadmium had much lower concentrations in the internal organs compared with copper and zinc. Considering the provisional tolerable weekly intake (PTWI) of the three heavy metals and the average intake of octopus per day, all three elements should have no adverse effects on humans.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1175-1176
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• 2012

• Korean Journal of Computational Design and Engineering
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• v.15 no.1
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• pp.70-83
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• 2010

Recently, floating cranes are mainly used to erect heavy blocks or cargos for constructing ships in many shipyards. It is important to estimate the dynamic motion of the heavy cargo suspended by a floating crane and the tension of the wire ropes between the floating crane and the heavy cargo. In this paper, the coupled dynamic equations of motion are set up for considering the 6 degree-of-freedom floating crane and the 6-degrees-of-freedom heavy cargo based on multibody system dynamics. Depending on the cargo weight, the motion of the floating crane would be changed to nonlinear state. The nonlinear terms in the equation of motion are considered. In addition, the nonlinear hydrostatic force, the linear hydrodynamic force, wire rope force, mooring force and gravity force are considered as the external forces. As the result of this paper, we analyze the engineering effect for erecting the heavy cargo by using the floating crane.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.7-13
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• 2020

In this study, a stabilization method was applied to stabilize heavy metals in soils collected from a domestic contaminated area and a Canadian mine site. The stabilizing agent used in the experiment was a solidifying agent developed by KERT Co., Ltd., Korea. The agent was applied to the samples at varying weight ratios of 0, 2, 5, 7, and 10% (w/w). and the concentrations of heavy metals in the effluent were monitored at predetemined time intervals. The results indicated that the stabilization efficiency of heavy metals (Cd, Cu, Pb) increased proportionally until the agent was increased to 5%, which showed almost no leaching of heavy metals after 28 days after agent application. Therefore, addition of 5% relative to soil mass was proposed to be the optimum dose for the stabilization agent.

• Food Science of Animal Resources
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• v.21 no.4
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• pp.337-343
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• 2001

Changes of Physicochemical compositions in domestic broiler chickens of different marketing standard range from 5ho (Korean traditional weight unite for chicken) to 16ho were assessed. The moisture contents of chicken breast were 74.00 ∼ 76.15% and there were no significant trend with weight difference. The chicken breasts of the light weight range(5ho∼8ho) contained high fat contents of 2.35∼2.78%. The chicken breasts of the heavy weight range(12ho∼16ho) contained low fat contents of 0.47 ∼0.66%. The chicken breasts of the heavy weight range had more protein contents than those of the light weight range. The chicken breast of the light weight range showed low Warner Braztler shear force (WBS) values when compared to those taken from chicken of the heavy weight range. However. there was no significant differences in water ho1ding capacity (WHC ) and cooking loss(p>0.05). In meat color the L* values (lightness) were 61.83∼71.33 and there were no significant differences for samples in different weight range except 5ho and 13ho. The b* valuers (yellowness) were 1.73 ∼6.79 and the values decreased with increasing chicken weight. In mineral composition. calcium and iron contents were decreased with increasing chicken weight. Phosphate, potassium and magnesium contents increased as weight ranges increased. The thigh meat separated from 11ho to 16ho had a similar tendency. In chemical composition(%). WBS, WBC. cooking loss, meat colors and mineral contents, compacted to breast in the same weight ranges. The results from this study would provide a basic information for establishment of marketing standard of chicken.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.667-671
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• 2005

The aim of this study is to investigate the effects of the muscle mass and fiber number on post-mortem metabolic rates and pork quality. Carcass traits, muscle fiber characteristics, and type of fiber composition were evaluated using a sample of 200 cross-bred pigs. The muscle mass was divided into two groups according to carcass weight and loin-eye area measurements (heavy or light). In addition, the muscle histological characteristics were divided into two groups according to the muscle fiber density and total number of muscle fibers (high or low). All the carcass traits were significantly different in the muscle mass groups. Increasing weight significantly affected the cross-sectional area (CSA) of all fibers. The low group, which had a low muscle fiber number indicating a larger CSA of fibers, and especially the heavy-low group had the highest CSA levels of fibers. The fiber number percentage and the area percentage were significantly different in the groups categorized by fiber number. The heavy-high group indicated a normal rate of pH decline and the R-value. In addition, pigs with a heavy muscle mass and high muscle fiber number indicated normal drip loss, lightness, and protein denaturation. The present results suggest that increasing the total muscle fiber number has a beneficial effect on increasing the muscle mass without deteriorating the meat quality.