• Korean Journal of Construction Engineering and Management
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• v.14 no.4
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• pp.97-107
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• 2013

Occupational safety and health management expense in construction industry means the monetary amount that the purchaser appropriates to prevent various disaster from happening during the construction period by setting aside a certain amount from subcontract based on the construction type and scale. The current appropriation standard of the Ministry of Employment and Labor has been enforced since its stipulation in 1988 although various policy changes for the safety in construction industry, e.g. the development of occupational safety management techniques in construction industry, changes in construction field site environment, cost depreciation, etc., are happening in Korea and overseas. Therefore, it is required at this point to examine whether the current occupational safety and health management expense appropriation is proper or not on the basis of time trend and the changes in the construction industry environment. Accordingly, this study aims at investigating the appropriation of occupational safety and health management expense for construction industry by the construction type and target expense in response to current construction industry environment and proposing the proper appropriation. The above research result proposes the calibration of the appropriation as specified and stipulated by the Ministry of Employment and Labor by the construction type and target expense, which is necessary to reflect the actual condition of the current construction industry environment.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.5-12
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• 2015

Since blasting noise is impact noise, it will give a sudden shock to the human. In the case, such as the blast vibration, it has given aging buildings and livestock great damage to move the vibration along ground in nearby regions. In this study, the influence of the blasting generated during excavation was analyzed for effects on regional. A couple of field and laboratory surveys about geological were carried out to figure out the geological ratio in the study-performed area. Blast vibration noise was compared to the domestic and abroad case studies and each of the institutions permissible standards established the most appropriate criteria in site condition. The vibration velocity of blasting vibration exploits the values which were measured from test blasting on the ground in order to examine blasting effect. Considering the blasting point as the shortest distance from safety facilities (farms, private houses, etc.), the examination of the influence range, which was derived from the vibration velocity of blasting vibration, was performed to figure out how the point affected the safety facilities. Three-dimensional numerical analysis was performed a time history analysis in order to analyze the behavior of the structure for a dynamic blast load, which was determined in three directions of the blast vibration value. The results of three-dimensional numerical analysis and the blasting effect of blasting vibration estimation equation blasting vibration of impact circle with accompanying test blasting were compared. And the analysis confirmed similar results figures.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.752-756
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• 2002

Green-emitting $Zn_2SiO_4:Mn$ phosphors for PDP(Plasma Display Panel) application were synthesized by colloidal seed-assisted spray pyrolysis process. The codoping with $Gd^{3+}/Li^+$, which replaces $Si^{4+}$ site in the willemite structure, was performed to improve the luminous properties of the $Zn_2SiO_4:Mn$ phosphors. The particles prepared by spray pyrolysis process using fumed silica colloidal solution had a spherical shape, small particle size, narrow size distribution, and non-aggregation characteristics. The $Gd^{3+}/Li^+$ codoping amount affected the luminous characteristics of $Zn_2SiO_4:Mn$ phosphors. The codoping with proper amounts of $Gd^{3+}/Li^+$ improved both the photoluminescence efficiency and decay time of $Zn_2SiO_4:Mn$ phosphor particles. In spray pyrolysis, the post-treatment temperature is another factor controlling the luminous performance of $Zn_2SiO_4:Mn$ phosphors. The $Zn_{1.9}SiO_4:Mn_{0.1}$ phosphor particles containing 0.1 mol% $Gd^{3+}/Li^+$ co-dopant had a 5% higher PL intensity than the commercial product and 5.7 ms decay time after post-treatment at $1,145^{\circ}C$.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.257-264
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• 2017

The PC (Precast Concrete) construction method is a technique where concrete members that have been produced in a plant are constructed on site. Thus, continuity and secure integration of a structure that can be obtained by connecting rebars at splicing joint for PC members are the main areas of concern for this method. To evaluate the splicing and bonding performance according to application of a splice sleeve for connecting rebar in this research study, the diameter of rebar, development length, grouting strength etc. were set as variables. The performance and stiffness of splicing according to the development length of grout strength were measured and evaluated. In addition, by conducting comparative analysis on each of the variables, the factors that affected the splice sleeve for connecting rebar were discussed. The results confirmed that the strength and stiffness of the splice sleeve for connecting rebar were significantly affected by the development length while the increase in performance according to grout strength was not as significant.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.2
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• pp.179-186
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• 2017

Because facial asymmetry is caused by various causes, the cause analysis is important and quantitative index is needed to the evaluation. In this study, we applied the Nottingham Grading System that was used as a quantitative index to evaluate the facial paralysis by tracking the markers through the image processing and calculating the distance between the markers with images obtained by using the webcam, to evaluate facial asymmetry. The existing Nottingham Grading System has a problem of causing a measurement error in the specific case because the left and right are compared by summing the distance change between the feature points of the face part according to the change of the facial expression. We compared the case of the facial asymmetry and case of normal subject by using the existing Nottingham Grading System and the improved Nottingham grading system. In the existing Nottingham Grading System, case of facial asymmetry and case of facial symmetry were 99.0% and 95.0% respectively in the normal range, but the improved Nottingham Grading System showed facial asymmetry case was 74.0% and facial symmetrical case was 93.2%. The results of experiment show that the improved Nottingham Grading System allows detailed evaluation of each site and improved the problem of the Nottingham Grading System for specific cases.

• Clean Technology
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• v.17 no.4
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• pp.370-378
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• 2011

Catalytic activity of $V_2O_5-WO_3/TiO_2$-based SCR catalyst was examined for the oxidation of gas-phase elemental mercury to oxidized mercury. Mercury species was not detected on the commercial SCR catalyst after the oxidation reaction of elemental mercury, regadless of the presence of HCl acting as oxidant and the reaction conditions. This suggests that elemental mercury oxidation by HCl could occur via a Eley-Rideal mechanism with gas phase or weakly-bound mercury on the surface of $V_2O_5-WO_3/TiO_2$ SCR catalyst. The activity for mercury oxidation was significantly increased with the increase of $V_2O_5$ loading, which indicates that $V_2O_5$ is the active site. However, turnover frequency for mercury oxidation was decreased with the increase of $V_2O_5$ loading, indicating the activity for mercury oxidation was strongly dependent on the surface structure of vanadia species. The activity for oxidation of elemental mercury under SCR condition was much less than that under oxidation condition at the same HCl concentration and reaction temperature.

• Fire Science and Engineering
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• v.33 no.4
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• pp.112-120
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• 2019

Benzene is a class 4 hazardous material according to the Act on the Safety Control of Hazardous Substances. This study qualitatively evaluated the damage size of a "toxic" accident and "pool fire" accidents based on benzene in a virtual scenario of a fire and leakage accident during unloading at a port facility. The KORA program was used as an evaluation method, which is supported as a universal program by the National Institute of Chemical Safety. The range of damage effects of a benzene-induced fire and leakage accident was predicted. In the case of toxic damage range, the accident's damage effect range for the "worst case scenario" was reduced by up to 5.11% with a decrease in the size of the leakage hole. In the case of the leakage time, the damage effect range increased to 145.12% with a 10 min leakage time compared to that of a 5 min leakage time and went up to 20 min (212.29%) with a 20 min leakage time. In the case of pool-fire-induced damage, the damage effect range by radiant heat in the "worst case scenario" was 228.8 m in radius from the center of the handling facility. In the "alternative scenario," the damage effect range by radiant heat was reduced by up to 8.26% compared to that in the "worst case scenario" since the size of the leakage hole was decreased by reducing the cross-sectional area of the pipe.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.481-486
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• 2008

Standard Estimating System, which can be used for estimating a construction cost, has been pointed out having some problems such as non-reflecting a variety of construction environments and site conditions, non-adapting new technologies and methods since it was established in 1970. For solving these problems, the Korean Institute of Construction Technology(KICT) has chosen organizations for amending Standard Estimating System. However they have had many mistakes in the process of amending works because of non-establishing amending process and absence of the depreciation measurement method. This research derived the necessity to improve the amending process of the Standard Estimating System, and presented the detailed amending process and the performing method in the each process. Furthermore, this research proposed the depreciation measurement method available for the construction industry by means of analyzing researches that performed in the manufacturing industry and the measurement method for depreciation of general accounts.

• Journal of the Korean association of regional geographers
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• v.16 no.1
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• pp.34-47
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• 2010

The purpose of this study is to investigate the actual condition of commercial use of housing site in residential development complexes, and to derive effective future development plan by analyzing the influence of penetrating factors of commercial use. The foJlowing are the results of the analysis. First, characteristics of roads showed that the wider the widths of roads adjoining individual lots have more influences on commercial use penetration. This means that non-residential facilities tend to be located on regions where frequencies of uses are high, preferring regions having good transportation accessibility. Second, characteristics of adjacent usage showed that the distances of common housing, neighborhood facilities, schools to single-detached residential units acted as a factor for higher penetration ratio of commercial use when they were closer.ors an opposite, it showed as distances to parks were further, the penetration ratio were higher. This can be inferred that the condition of detached houses located closer to parks have pleasure environment, and act as a factor preventing commercial use penetration. Third, the official land price presents as a form of quality, as the analysis showed that the higher official land price, the more it acts as a factor increasing the penetration ratio of commercial use.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.277-284
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• 2015

In order to analyze the contamination level of sediment samples taken from Chusori and Chudong areas in Daechung Reservoir, the particle size and concentrations of organics and nutrients were analyzed and phosphorus fractionation analysis was conducted. The average fraction of silt-sized particles was 92% in the sediments taken from Chudong area and Chusori area at the site adjacent to main current, which was higher than that from the upper Chusori area. The concentrations of total phosphorus in the sediments at Chusori and Chudong area were 999 (${\pm}98$) and 1,123 (${\pm}119$) mg/kg sediment, respectively. The fractions of autochthonous phosphorus, which can be readily eluted by change of environmental conditions, were much higher than those of allochthonous phosphorus, indicating the internal load can contribute the eutrophication in these areas. The concentrations of total nitrogen were over 5,600 mg/kg sediment in all samples, which is the guideline of Contamination Assessment of River and Lake Sediments of the Ministry of Environment, indicating the contamination level of total nitrogen is serious in the sediments. It is concluded that the countermeasures to manage the quality of sediments are required to improve the water quality in the Daechung Reservoir.