• Korean Journal of Poultry Science
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• v.38 no.1
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• pp.1-4
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• 2011

A 35-day trial was conducted to examine the influence of floor density on the behaviour of broiler chickens. Day-old male broilers (n=756) were randomly assigned to one of four stocking densities (6 replicates of n=13, 25, 38 and 50) in 24 identical 2.6 $m^2$ pens. These stocking densities were coded very low (VL), low (L), medium (M) and high (H) and contained a floor space allowance per bird of 2,000 $cm^2$, 1,000 $cm^2$, 667 $cm^2$ and 500 $cm^2$, respectively. Scan sampling of all groups was carried out at 15-min intervals during two 1-h periods (10.00 h~11.00 h and 14.00 h~15.00 h) for five days each week. The numbers of birds engaged in different behavioural activities were recorded. It was found that the most common behaviour in all densities was lying. There was no clear effect of density during wks 1~4 of the trial, but in wk 5 birds in the L, M and H groups showed lower levels (P=0.07) of lying behaviour when compared to birds in the VL group suggesting that an increase in animal density results in decreased opportunities for undisturbed rest. This observation is supported by standing and walking behaviour, which was lower (P<0.05) in the VL group in wk 5. Foraging behaviour measured in the study by the numbers of birds pecking the ground declined as the trial progressed, but scratching increased in 2 wk then decreased. Birds in the VL group showed higher (P<0.05) level of pecking the ground behaviour compared to birds in the L, M and H groups, but scratching behaviour higher (P<0.05) and lower (P<0.05) in VL of 1 wk and 2 wk respectively. However, a peak in aggressive behaviour was observed in wk 2 and birds in the VL group showed less (P<0.05) agonistic behaviour than birds in the H and M groups. Other behaviours (dustbathing, preening, eating or drinking) were not influenced (P>0.05) by stocking density.

• Journal of the Korean Society for Railway
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• v.13 no.1
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• pp.119-124
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• 2010

Light rail is an electric railway system, characterized by its ability to operate single or multiple car consists (trains) along exclusive rights-of-way at ground level, on aerial structures, in subways or in streets, able to board and discharge passengers at station platforms or at street, track, or car-floor level and normally powered by overhead electrical wires. Depending upon the specific system, the light rail lends some major advantages to urban settings. The evaluation of light rail technology as a potential component of regional transit systems has been the subject of extensive studies throughout the country in the past decade. For the study, feasibility was defined as "the ability of an LRT system to achieve certain level of transportation market in comparison with other transportation alternatives." This paper describes the feasibility study to evaluate a proposed light rail development project. The minimum are those LRT systems that would met to make a project feasible for further evaluation.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.1
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• pp.1-8
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• 2020

In 2016, an earthquake occurred at Gyeongju, Korea. At the Wolsong site, the observed peak ground acceleration was lower than the operating basis earthquake (OBE) level of Wolsong nuclear power plant. However, the measured spectral acceleration value exceeded the spectral acceleration of the operating-basis earthquake (OBE) level in some sections of the response spectrum, resulting in a manual shutdown of the nuclear power plant. Analysis of the response spectra shape of the Gyeongju earthquake motion showed that the high-frequency components are stronger than the response spectra shape used in nuclear power plant design. Therefore, the seismic performance evaluation of structures and equipment of nuclear power plants should be made to reflect the characteristics of site-specific earthquakes. In general, the floor response spectrum shape at the installation site or the generalized response spectrum shape is used for the seismic performance evaluation of structures and equipment. In this study, a generalized response spectrum shape is proposed for seismic performance evaluation of structures and equipment for nuclear power plants. The proposed response spectrum shape reflects the characteristics of earthquake motion in Korea through earthquake hazard analysis, and it can be applied to structures and equipment at various locations.

• Environmental Analysis Health and Toxicology
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• v.24 no.3
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• pp.203-211
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• 2009

A lesser degree of research is available with respect to indoor radon characteristics associated with occupants' exposure. The present study evaluated the radon levels in several public-access buildings or underground facilities, and their temporal variation in underground facilities. Radon measurements were conducted in 2005 and 2006, utilizing a continuous radon detector. A solid alpha detector (RAD7) was utilized to measure indoor radon levels. The mean radon concentrations obtained from the building or facilities were in a descending order: platforms of Daegu subway line 2, 2005 (32 $Bq/m^3$), hot-air bathroom (14 $Bq/m^3$), basement of office building (14 $Bq/m^3$), underground parking garage (14 $Bq/m^3$), underground shop (12 $Bq/m^3$), nursery (10 $Bq/m^3$), platforms of Daegu subway line 2, 2006 (9.0 $Bq/m^3$), platforms of Daegu subway line 1, 2006 (8.9 $Bq/m^3$), supermarket (7.9 $Bq/m^3$), hospital (7.3 $Bq/m^3$), and second-floor of office building (5.7 $Bq/m^3$). In general, underground-level facilities exhibited higher radon levels as compared with ground-level facilities. It was suggested that ventilation is an important parameter regarding the indoor levels of a subway. There was a decreasing or increasing trend in hourly-radon levels in a subway, whereas no trend were observed in a basement of office building. In addition, the radon levels in the subway lines 1 and 2 varied according to the platforms. The radon levels in the present study were much lower than those of previous studies. The average annual effective dose (AED) of radiation from indoor radon exposure was estimated to be between 0.043 and 0.242 mSv/yr, depending on facility types. These AEDs were substantially lower than the worldwide average AED (2.4 mSv/yr).

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.111-118
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• 2009

This study is to analyze the performance of SWH(Solar Water Heating) and GSHP(Ground Source Heat Pump) systems by evaluating their energy efficiency and LCC(Life Cycle Cost) as being applied to the OO hall as a selected building in the Army. The OO hall, used as bathrooms, dining rooms, accommodations and offices, has reinforced concrete structure system with three floors above the ground and one underground, and its total floor area is approximately 2,917$m^2$. Two energy simulations are conducted to predict the yearly cooling and heating energy of the selected building: One is for analysis of an air-conditioning energy consumption using the e-Quest program, and another is for two new-renewable energy facilities as a water heating source using the RETScreen. The installed capacity of two new-renewable energy facilities is determined according to the 5% level of total standard construction cost. As a briefly result, SWH system is more energy-effective than GSHP system. Considering the break-even point, it is expected that SWH can take only 3 years 11 months to pay for itself in savings while the investment of GSHP can be recovered in more than 16 years 6 months.

• Asian Journal of Atmospheric Environment
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• v.6 no.2
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• pp.73-82
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• 2012

This study was aimed to thoroughly estimate the characteristics of indoor particulate matter (PM) collected on subway platforms by the cooperative approach of semi-bulk and single particle analyses. The size-resolved PM and its number concentration were measured on the platform in a heavily traveled subway station in Fukuoka, Japan. Particle Induced X-ray Emission (PIXE) and micro-PIXE techniques were applied to the chemical analyses of semi-bulk and single particle, respectively. There was the close resemblance of timely fluctuation between PM number concentration and train service on the third basement floor (B3F) platform compared to the second basement floor (B2F) and its maximum level was marked in rush hour. Higher number counts in large particles ($>1{\mu}m$) and lower number counts in fine particles ($<1{\mu}m$) were shown on the platform compared to an above ground. PM2.5 accounted for 58.2% and 38.2 % of TSP on B3F and on B2F, respectively. The elements that were ranked at high concentration in size-resolved semi-bulk PM were Fe, Si, Ca, S, and Na. The major elements tending to have more elevated levels on B3F than B2F were Fe (4.4 times), Ca (17.3 times), and Si (46.4 times). Although concentrations were very low, Cr ($11.9ng\;m^{-3}$ on B3F, $2.4ng\;m^{-3}$ on B2F), Mn ($3.4ng\;m^{-3}$ on B3F, $0.9ng\;m^{-3}$ on B2F), and Pb ($0.6ng\;m^{-3}$ on B3F, $1.6ng\;m^{-3}$ on B2F) were detected from PM2.5. Individual PM was nearly all enriched in Fe with Si and Ca. Classifying and source profiling of the individual particles by elemental maps and particle morphology were tried and particles were presumably divided into four groups (i.e., train/rail friction, train-rail sparking, ballast/abrasive, and cement).

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.4
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• pp.271-277
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• 2020

There are increasing cases of monitoring the structural response of structures using multiple sensors. However, owing to cost and management problems, limited sensors are installed in the structure. Thus, few structural responses are collected, which hinders analyzing the behavior of the structure. Therefore, a technique to predict responses at a location where sensors are not installed to a reliable level using limited sensors is necessary. In this study, a numerical study is conducted to predict the seismic response of low-rise buildings using limited information. It is assumed that the available response information is only the acceleration responses of the first and top floors. Using both information, the first natural frequency of the structure can be obtained. The acceleration information on the first floor is used as the ground motion information. To minimize the error on the acceleration history response of the top floor and the first natural frequency error of the target structure, the method for predicting the mass and stiffness information of a structure using the genetic algorithm is presented. However, the constraints are not considered. To determine the range of design variables that mean the search space, the parameter prediction method based on artificial neural networks is proposed. To verify the proposed method, a five-story structure is used as an example.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.322-327
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• 2012

Fate of fenitrothion aerially sprayed to control pine wood nematode (Bursaphelenchus xylophilus) was studied in a forest of Haman area. And the monitoring of fenitrothion was conducted in a stream flowed from forest area of Gijang sprayed fenitrothion. Fenitrothion 50% EC was diluted 100 times and applied two or three times using helicopter in Haman and Gijang, respectively. Average fenitrothion deposits on forest floor ranged from 6% of standard aerial application rate. Following to the second application, fenitrothion deposits in the pine needle ranged from 0.6 to 0.9 mg/kg and then rapidly decreased to 0.01 mg/kg after 109 days. Deposits on the plant washed off by rainfall and reached to soil surface was 1.3% of the application rate. All of fenitrothion on the ground resided in the forest floor covering the soil surface, where fenitrothion residues were decreased to a tenth at 109 days after the second application, but they were not detected in sol beneath it. And the only low level of fenitrothion residues, 0.0009 mg/L, was detected in runnel of the experimental forest just after aerial application. The concentration of fenitrothion in effluent from Gijang area was less than detection limit (0.0001 mg/L) during the entire period.

• Korean Journal of Applied Biomechanics
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• v.27 no.3
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• pp.189-195
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• 2017

Objective: The aim of this study was to examine the effect of foot landing type (forefoot vs. rearfoot landing) on kinematics, kinetics, and energy absorption of hip, knee, and ankle joints. Method: Twenty-five healthy men performed single-leg landings with two different foot landing types: forefoot and rearfoot landing. A motion-capture system equipped with eight infrared cameras and a synchronized force plate embedded in the floor was used. Three-dimensional kinematic and kinetic parameters were compared using paired two-tailed Student's t-tests at a significance level of .05. Results: On initial contact, a greater knee flexion angle was shown during rearfoot landing (p < .001), but the lower knee flexion angle was found at peak vertical ground reaction force (GRF) (p < .001). On initial contact, ankles showed plantarflexion, inversion, and external rotation during forefoot landing, while dorsiflexion, eversion, and internal rotation were shown during rearfoot landing (p < .001, all). At peak vertical GRF, the knee extension moment and ankle plantarflexion moment were lower in rearfoot landing than in forefoot landing (p = .003 and p < .001, respectively). From initial contact to peak vertical GRF, the negative work of the hip, knee, and ankle joint was significantly reduced during rearfoot landing (p < .001, all). The contribution to the total work of the ankle joint was the greatest during forefoot landing, whereas the contribution to the total work of the hip joint was the greatest during rearfoot landing. Conclusion: These results suggest that the energy absorption strategy was changed during rearfoot landing compared with forefoot landing according to lower-extremity joint kinematics and kinetics.

• Advances in concrete construction
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• v.6 no.2
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• pp.177-197
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• 2018

This paper presents a case study about the damages on the structural elements of a cast in place reinforced concrete (RC) building after a big fire which was able to be controlled after six hours. The fire broke off at the $2^{nd}$ basement floor of the building, which has five basements, one ground, and two normal floors. As a result of intensely stocked ignitable materials, it spread out to the all of the upstairs. In visual inspection, most of the typical fire damages were observed (such as spalling, net-like cracks, crumbled plasters, bared or visible reinforcement). Also, failures of the $2^{nd}$ basement columns were encountered. It has been concluded that the severity failures of the columns at the $2^{nd}$ basement caused utterly deformation of the building, which is responsible for the massive damages on the beam-column connections. All of the observed damages were categorized related to the types and presented separated regarding the floors. Besides to the visual inspection, the numerical analysis was run to verify the observed damaged on the building for columns, beams, and the connection regions. It is concluded from the study that several parameters such as duration of the fire, level of the temperature influence on the damages to the RC building. Also, it is highlighted by the study that if the damaged building is considered on the overall structural system, it is not able to satisfy the minimum service requirements neither gravity loads nor earthquake conditions.