• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.213-221
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• 2011

The purpose of sewer system is to separate rain water from sewage water. Through this, it is possible to prevent the flood and preserve public water territory. For the past few years, many problems of the sewer system have been solved by the execution of sewer rehabilitation project. However, they still exist in sewer system caused by I/I, which are divided into infiltration and inflow. Infiltration means the rain water and underground water that infiltrate through breakage point on pipes, inflow means the water that flows in through misconnection on pipes. This study shows how the I/I calculation has changed according to the new standardized manual and identifies the I/I difference between the new calculation and the existing one. Through the analysis on the two calculation methods we examined the appropriacy of the new method by comparing it to the old one. The result points out that the new standardized manual is more appropriate than the old in aspect of objectivity and reproducibility(establish standardization), rationality(alteration of inflow unit).

• Bulletin of the Society of Naval Architects of Korea
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• v.15 no.1
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• pp.7-9
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• 1978

In this calculation of statical stability of a ship, mechanical integrator was used most popularly and the direct calculation method such as a Barn's wedge method was also adopted in some cases. Both of the above method was developed for manual calculation which include mechanical integration or drafting procedure on body plan. Therefore, the computerization of stability calculation by the above method is very difficult. In this paper a simplified method for stability calculation is suggested, with based on hydrostatic data and immerged wedged characteristics.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.444-449
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• 2023

The current study involved the calculation of air pollutant emission factors (EFs) generated from the incineration of agricultural residues. The process included sample collection, weight measurement, moisture measurement, incineration system configuration, and concentration measurement. The average CO emission factor of gaseous air pollutants from the incineration of barley and wheat agricultural residues was calculated as 0.08289 kg/kg and 0.06665 kg/kg, respectively, whereas the average NO_X emission factor for barley and wheat agricultural residues was determined to be 0.00518 kg/kg and 0.00185 kg/kg, respectively. In the existing air pollutant emission calculation manual, the EF is presented only for barley. Therefore, in this study, we have introduced the EF for wheat, previously absent in the calculation manual. Additionally, the air pollutant calculation manual presents the EF of air pollutants as one value, but in this study, EF values corresponding to 2.5% and 97.5% were presented in consideration of the distribution of experimental values as shown in EMEP/EEA data.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.87-93
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• 1993

Many methods to assess hazards caused by the risks increased with the growth of petrochemical industry. The manual of International Atomic Energy Agency which was much more applied to quantitative analysis of the real situation and the CPQRA is introduced to verify the theoretical background of this manual. Than other methods, as a result, we can see that this manual, which is simple to use and requires a little information, shows similar results to those of calculation by numerical formula. Also, the program code of this manual was materialized and if it is possible to obtain adequate parameters to our circumstance, the manual will be quite useful in early risk analysis.

• Journal of the Optical Society of Korea
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• v.18 no.1
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• pp.23-31
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• 2014

Recently, the number of camera companies that produce commercializing interchangeable lens systems such as digital single lens reflex (DSLR) and compact system camera (CSC) lenses has been gradually increasing. These interchangeable lenses have various kinds of lenses with distinct specifications. In particular, the distance window among these specifications is the function most preferred by customers. Mechanical manual zoom and manual focus in these high end camera lenses with a distance window are in particular desirable specifications and are required for product quality. However, the AF lens group is linked to the zoom cam and moves. Because the AF lens group moves along with the object distance, we can not realize the distance window with only zoom locus calculation. In this paper, in order to solve the problem, we suggest an optical calculation method for a corrected AF zoom cam for an interchangeable lens with a distance window to achieve product differentiation and analyze the error in the calculation.

• Fire Science and Engineering
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• v.29 no.1
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• pp.73-79
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• 2015

There are three kinds of design method of the fire sprinkler systems. Grid type is connected all branch as a trapezoid. Loop type is connected cross-mains like circle. The last one is a tree type most commonly used. Grid type needs computer program to calculate the friction loss and flow rate apart from very simple form. In loop type, manual calculation is possible. Design engineer can draw up and calculate the demands without computer program. Because water supplies two direction in loop type, friction loss is smaller than tree type. Water distribution in operation area is uniform because of the small differences of sprinklers discharge pressure. Loop type is superior to tree type in respect of total pressure and flow rate. Using the small diameter pipe, the labor and construction cost will be decreased in the end. Loop type sprinkler design is rarely laid out because design engineers don't know the method. This paper is intended to inform that the loop type is better than the tree type in performance and economic point of view. And also this paper intend to use the loop type easily and widely.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1049-1055
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• 2023

The utilization of agricultural drones for pest control operations has been increasing due to its economic efficiency. However, variations in the effectiveness of these operations occur depending on the operator's proficiency. In this study, we applied a smart operating mode to overcome the limitations of manual flight mode and proposed a numerical model. Through comparative validation with prior research, we conducted experimental verification. As a result, we determined the spray time and calculation of spray area for each drone model. We selected a drone for pest control with a high similarity to the numerical model and verified it experimentally. Through this, we confirmed that the application of the smart operating mode is more effective in terms of calculation of spray area and operational efficiency compared to manual flight mode.

• Bulletin of the Society of Naval Architects of Korea
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• v.14 no.3
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• pp.1-4
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• 1977

The computer aided ship design and construction has become very popular one in a ship yard recently. For one of such a purpose a program is developed with Aitken's iterative interpolation method. From the sample calculation we can conclude that the program has a reliable acquracy for the calculation of hydrostatic data or loading manual. And also the program can be applicable to a ship construction by careful selecting of input data.

• Radiation Oncology Journal
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• v.5 no.2
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• pp.165-168
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• 1987

The generalized Bathe method, proposed by Webb and Fox, which is a method of calculation of dose correction factor for the purpose of heterogeneous tissue, is complex even for a few kind of tissues. The method was modified for the purpose of getting a simple method that divide the multilayer of heterogeneous tissues into some groups of adjacent-tissue pairs. This new method could reduce the number of exponential terms and the time for calculating the dose correction factors by manual and computer calculation.

• Journal of the Korean Society of Safety
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• v.10 no.1
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• pp.56-63
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• 1995

Two methods of the numerical method of CPQRA(Chemical Process Quantitative Risk Analysis) and the manual method of IAEA(International Atomic Energy Agency) were used to estimate the individual risk and societal risk around the chemical plant. Where, the CPQRA is introduced to verify the theoritical background of the manual of international atomic energy agency. The Gaussian plume model which has a weather stability class D with velocity of 5m/s was applied to calculate dispersion of hazard material. Also, 8-point method was employed to the effects of accidents for wind distribution. Furthermore, historical record, FTA(Fault Tree Analysis) and ETA(Event Tree Analysis) were used to estimate the probability or frequency of accidents. Eventually, the individual risk shows isorisk contour and the societal risk shows F-N curve around hazard facility, especially in chemical plants. Caulculated results, which both individual and societal risk, by using IAEA manual show simillar results to those of calculation by numerical method of CPQRA.