• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.99-113
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• 2021

In these days, as cyberspace has been recognized as the fifth battlefield area following the land, sea, air, and space, attention has been focused on activities that view cyberspace as an operational and mission domain in earnest. Also, in the 21st century, cyber operations based on cyberspace are being developed as a 4th generation warfare method. In such an environment, the success of the operation is determined by the commander's decision. Therefore, in order to increase the rationality and objectivity of such decision-making, it is necessary to systematically establish and select a course of action (COA). In this study, COA is established by using the method of classifying operational elements necessary for cyber operation, and it is intended to suggest a direction for quantitative evaluation of COA. To this end, we propose a method of composing the COES (Cyber Operational Elements Set), which becomes the COA of operation, and classifying the cyber operational elements identified in the target development process based on the 5W1H Method. In addition, by applying the proposed classification method to the cyber operation elements used in the STUXNET attack case, the COES is formed to establish the attack COAs. Finally, after prioritizing the established COA, quantitative evaluation of the policy was performed to select the optimal COA.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.108-117
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• 2023

Background: When particles are absorbed into the human body, they penetrate deep into the lungs and interact with the tissues of the body. Heavy metals in PM_2.5 can cause various diseases. The main source of PM_2.5 emissions in South Korea's atmosphere has been surveyed to be places of business. Objectives: The concentration of heavy metals in PM_2.5 near the Ulsan Industrial Complex was measured and a health risk assessment was performed for residents near the industrial complex for exposure to heavy metals in PM_2.5. Methods: Concentrations of heavy metals in PM_2.5 were measured at four measurement sites (Ulsan, Mipo, Onsan, Maegok) near the industrial complexes. Heavy metals were analyzed according to the Air Pollution Monitoring Network Installation and Operation Guidelines presented by the National Institute of Environmental Research. Among them, only five substances (Mn, Ni, As, Cd, Cr⁶⁺) were targeted. The risk assessment was conducted on inhalation exposure for five age groups, and the excess cancer risk and hazard quotient were calculated. Results: In the risk assessment of exposure to heavy metals in PM_2.5, As, Cd, and Cr⁶⁺ exceeded the risk tolerance standard of 10^-6 for carcinogenic hazards. The highest hazard levels were observed in Onsan and Mipo industrial complexes. In the case of non-carcinogenic hazards, Mn was identified as exceeding the hazard tolerance of 1, and it showed the highest hazard in the Ulsan Industrial Complex. Conclusions: This study presented a detailed health risk from exposure to heavy metals in PM_2.5 by industrial complexes located in Ulsan among five age groups. It is expected to be utilized as the basis for preparing damage control and industrial emission reduction measures against PM_2.5 exposure at the Ulsan Industrial Complex.

• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.44-51
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• 2023

Nitrogen fertilizer is an essential macronutrient that requires repeated input for crop cultivation. Excessive use of nitrogen fertilizers can adversely affect the environment by discharging NH₃, NO, and N₂O into the air and leaching into surrounding water systems through rainfall runoff. Therefore, it is necessary to develop a technology that reduces the amount of nitrogen fertilizer used without compromising crop yields. Fertilizer deep placement could be a technology employed to increase the efficiency of nitrogen fertilizer use. In this study, a deep fertilization device that can be coupled to a tractor and used to inject fertilizer into the soil was developed. The deep fertilization device consisted of a tractor attachment part, fertilizer amount control and supply part, and an underground fertilizer input part. The fertilization depth was designed to be adjustable from the soil surface down to a depth of 40 cm in the soil. This device injected fertilizer at a speed of 2,000 m²/hr to a depth of 25 to 30 cm through an underground fertilizer injection pipe while being attached to and towed by a 62-horsepower agricultural tractor. Furthermore, it had no difficulty in employing various fertilizers currently utilized in agricultural fields, and it operated well. It could also perform fertilization and plowing work, thereby further simplifying agricultural labor. In this study, a newly developed device was used to investigate the effects of deep fertilizer placement (FDP) compared to those with urea surface broadcasting, in terms of rice and soybean grain yields. FDP increased the number of rice grains, resulting in an average improvement of 9% in rice yields across three regions. It also increased the number of soybean pods, resulting in an average increase of 23% in soybean yields across the three regions. The results of this study suggest that the newly developed deep fertilization device can efficiently and rapidly inject fertilizer into the soil at depths of 25 to 30 cm. This fertilizer deep placement strategy will be an effective fertilizer application method used to increase rice and soybean yields, in addition to reducing nitrogen fertilizer use, under conventional rice and soybean cultivation conditions.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.175-185
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• 2016

In this study, manufactured experimental pig house (two pig house) and compared the changes in internal temperature and energy depending on the application of UTC control system for their utilizing of them as basic data for maintaining proper conditions for feeding environment and reducing heating energy depending on the UTC control system and program development, prior to applying the UTC system into pig house, representative agricultural facility. The control system ranges T1~T4 which is made to control a total of five output signals O1~O5 in the way of On/Off by using the algorithms of the program after measuring temperature scored 4 of total. Temperature setting was controlled with 28.0℃ in experimental pig house and 34.0℃ in UTC plenum, and output signal was controlled by comparing it with the measured temperature. During 3 days, the maximum temperature were measured at an average 31.8℃ when operated the control system in pig house. At the same time, the maximum temperature were measured 36.6℃ in comparison pig house, it was low temperature at 4.8℃ in experimental pig house than comparison pig house. Also, UTC plenum temperature was showed that rose at an average 50.5℃ by operation of the control program.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.367-373
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• 2023

Aircrews and passengers are exposed to radiation from cosmic rays and secondary scattered rays generated by reactions with air or aircraft. For aircrews, radiation safety management is based on the exposure dose calculated using a space-weather environment simulation. However, the exposure dose varies depending on solar activity, altitude, flight path, etc., so measuring by route is more suggestive than the calculation. In this study, we developed an instrument to measure the cosmic radiation dose using a general-purpose Si sensor and a multichannel analyzer. The dose calculation applied the algorithm of CRaTER (Cosmic Ray Telescope for the Effects of Radiation), a space radiation measuring device of NASA. Energy and dose calibration was performed with Cs-137 662 keV gamma rays at a standard calibration facility, and good dose rate dependence was confirmed in the experimental range. Using the instrument, the dose was directly measured on the international line between Dubai and Incheon in May 2023, and it was similar to the result calculated by KREAM (Korean Radiation Exposure Assessment Model for Aviation Route Dose) within 12%. It was confirmed that the dose increased as the altitude and latitude increased, consistent with the calculation results by KREAM. Some limitations require more verification experiments. However, we confirmed it has sufficient utilization potential as a cost-effective measuring instrument for monitoring exposure dose inside or on personal aircraft.

• Convergence Security Journal
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• v.22 no.5
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• pp.95-105
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• 2022

The Army, Navy, and Air Force are making various efforts to develop a weapon system that incorporates the 4th industrial revolution technology so that it can be used in multi-domain operations. In order to effectively demonstrate the integrated combat power through the weapon system to which the new technology is applied, it is necessary to establish a network environment in which each weapon system can transmit and receive information smoothly. For this, it is essential to analyze the Information Exchange Requirement(IER) of each weapon system, but many IER analysis studies did not sufficiently reflect the various considerations of the actual tactical network. Therefore, this study closely analyzes the research methods and results of the existing information exchange requirements analysis studies. In IER analysis, the size of the message itself, the size of the network protocol header, the transmission/reception structure of the tactical network, the information distribution process, and the message occurrence frequency. In order to be able to use it for future IER prediction, we present a technique for calculating the information exchange requirement as a probability distribution using the Poisson distribution and the probability generating function. In order to prove the validity of this technique, the results of the probability distribution calculation using the message list and network topology samples are compared with the simulation results using Network Simulator 2.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5B
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• pp.497-507
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• 2010

Climate changes affect greatly natural ecosystem, human social and economic system acting on constituting the climate system such as air, ocean, life, glacier and land, etc. and estimating the current impact of climate change would be the most important thing to adapt to the climate changes. This study set the target area to Nakdong river watershed and investigated the impact of climate changes through analyzing precipitation tendency, and to understand the impact of climate changes on hydrological elements, analyzed elasticity of precipitation-streamflow. For the analysis of precipitation trend, collecting the precipitation data of the National Weather Service from major points of Nakdong river watershed, resampling them at the units of year, season and month, used as the data of precipitation trend analysis. To analyze precipitation-streamflow elasticity, collecting area average precipitation and long-term streamflow data provided by WAMIS, annual and seasonal time-series were analyzed. In addition, The results of this study and elasticity, and other abroad study compared with the elasticity analysis and the validity of this study was verified. Results of this study will be able to be utilized for study on a plan to increase of flood control ability of flooding constructs caused by the increase of streamflow around Nakdong river watershed due to climate changes and on a plan of adapting to water environment according to climate changes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.517-527
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• 2023

Objectives: We examine cases of chemical poisoning that occurred in the cleaning of metal parts and the regulations on halogenated solvents in other countries and propose regulations necessary to prevent chemical poisoning from halogenated solvents. Methods: We collected cases of chemical poisoning through the website of the Korea Occupational Safety and Health Agency. A review of the literature was conducted focusing on regulations related to halogenated solvents in the United States and the European Union, particularly for cleaning metal parts. Among the Material Safety Data Sheets submitted to the government, MSDS containing eleven substances were extracted to confirm the composition and product use. We investigated cleaning methods for metal parts used in South Korea. For the hazard classification, the European Chemicals Agency or Japan's NITE's website was used. Results: In the case of poisoning, the cleaning methods involving trichloromethane were dipping and dry, which was not found in the literature. It was confirmed that many halogenated solvents and dimethyl carbonate were used for metal cleaning in South Korea. In vapor degreasing using TCE in the USA, even if the facility is strictly managed, such as by installing cooling coils in open cleaning facilities, the risk of exposure to TCE is considered to be not only carcinogenic but also a concern for acute and chronic effects. In comparison, exposure through Korean work methods such as dipping and drying operations is inevitably much higher. Conclusions: The transition to water-based cleaning with low-hazard chemicals should be a priority in the cleaning process. In the case of metal parts that require precise cleaning, if the use of a halogenated solvent is inevitable, a closed degreasing facility should be used to minimize exposure. The current regulations in the Occupational Safety and Health Act, the Chemical Substances Control Act, and the Air Environment Conservation Act do not require cleaning facilities to minimize emissions. To protect the health of workers using halogenated solvents to clean metal parts, regulations that require a fundamental reduction in exposure will be necessary.

• Journal of Korea Port Economic Association
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• v.39 no.3
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• pp.47-60
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• 2023

A thorough inventory of ship emissions, particularly ship's emission of in-port area is necessary to identify significant sources of exhaust gases such as NOx, SOx, PM, and CO₂ and trends in emission levels over time, and reduce their serious effects on the environment and human health. Therefore, the goal of this study is to assess the volume of emissions from ships in Mokpo port, which serves as a gateway to the southwest coast of Korea, using a bottom-up methodology and data from the automatic identification system (AIS) and the Korean Port Management Information System (Port-MIS). In this work, an analysis of ship movement utilizing AIS data and an actual set of data on ship specification were gathered. By examining ship movement using AIS data, We also proposed a new approach for identifying cruising/maneuvering mode. Finally, the results were classified by ship operating mode, by exhaust gas, by ship type, and by berth, which provides a thorough and in-depth analysis of the air pollution caused by ships in Mokpo port.

• Journal of Venture Innovation
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• v.5 no.2
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• pp.85-99
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• 2022

Dryers becoming commercially available for experimental and industrial use are classified to general drying oven, hot-air dryer, vacuum dryer, freezing dryer, etc. and kinds of them are various from the function, size and volume, etc. But the moisture measurement is not applied although it is important factor for the quality control and the performance improvement of products, and then now is very passive because the weight is weighed arbitrarily after dry-end. Generally the method for measuring moisture is divided by a direct measurement method and a indirect measurement method, and the former such as the change of weight or volume on the front and rear of separation of moisture, etc. is mainly used. Relatively a indirect measurement is very limited to apply due to utilize measurement apparatuses using temperature conductivity and micro-wave etc. In this research, we easily designed the moisture measurement system using the open-source based Arduino, and monitored moisture fluctuations and weight profiles in the real-time without the effect of external environment. Concretely the temperature-humidity and load cell sensors were packaged into a drying oven and the various change values were measured, and their sensors capable to operate 60℃ and 80℃ were selected to suitable for the moisture sensitive materials and the food dry. And also the performance safety using the organic samples of banana, pear, sawdust could be secured because the changes of evaporation rate as the dry time and temperature, and the measurement values of load cell appeared stable response characteristics through repeated experiments. Hereafter we judge that the reliability can be improved increasingly through the expansion of temperature-humidity range and the comparative analysis with CFD(Computational Fluid Dynamics) program.