• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.121-126
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• 2019

Metabolic profile test is used to evaluate nutritional imbalance and metabolic disease in dairy cows. The reference intervals of metabolic parameters may change according to nation, region, decades, and maintenance system. Despite the need to be periodically updated for the reference intervals of metabolic parameters, it has rarely been investigated in Korea. Therefore, this aim of study was to provide the reference intervals of metabolic parameters using dairy cows surveyed in Korea during recent years. A metabolic profile test was conducted for 2,976 clinically healthy dairy cows in Korea. Blood samples were collected for the analysis of serum metabolites. This study provided reference intervals of thirteen metabolic parameters (${\beta}$-hydroxybutyrate [${\beta}-HB$], non-esterified fatty acids [NEFA], glucose, total cholesterol [T-COL], total protein, albumin, globulin, blood urea nitrogen [BUN], aspartate aminotransferase [AST], gamma-glutamyl transferase [GGT], calcium, phosphorus, and magnesium). BUN and AST values of the current study were higher than those of previous studies. In the present study, the other metabolic parameters showed low or similar value compared to previous results. Moreover, ${\beta}-HB$, NEFA, T-COL, ALB, BUN, AST, and GGT values were affected by lactation period. This study provided information on the reference intervals of metabolites in healthy dairy cows in Korea. The reference intervals from the present study would be useful in managing and diagnosing disease of dairy cows. However, careful attention should be given in interpreting disease condition for metabolites affected by lactation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.446-452
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• 2021

As a higher standard for food consumption is required, the consumption of chicken meat that can satisfy the subdivided food preferences is increasing. In March 2003, the quality criteria for chicken carcasses notified by the Livestock Quality Assessment Service suggested quality grades according to fecal contamination and the size and weight of blood and bruises. On the other hand, it is too difficult for human inspection to qualify mass products, which is key to maintaining consistency for grading thousands of chicken carcasses. This paper proposed the computer vision algorithm as a non-destructive inspection, which can identify chicken carcass parts according to the detailed standards. To inspect the chicken carcasses conveyed at high speed, the image calibration was involved in providing robustness to the side effect of external lighting interference. The separation between chicken and background was achieved by a series of image processing, such as binarization based on Expectation Maximization, Erosion, and Labeling. In terms of shape analysis of chicken carcasses, the features are presented to reveal geometric information. After applying the algorithm to 78 chicken carcass samples, the algorithm was effective in segmenting chicken carcass against a background and analyzing its geometric features.

• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.79-88
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• 2022

Cable-supported bridges, as important large infrastructures, require a long-term and systematic maintenance strategy. In particular, various methods have been proposed to secure safety for the bridges, such as installing various types of sensor on members in the bridges, and setting management thresholds. It is evidently necessary to propose a strategic plan to efficiently manage increasing number of cable-supported bridges and data collected from a number of sensors. This study aims to develop an analysis tool that can automatically remove abnormal signals and calculate statistical results for the purpose of efficiently analyzing a wide range of data collected from a long span bridge measurement system. To develop the tool, basic information such as the types and quantity of sensors installed in long span bridges and signal characteristics of the collected data were analyzed. Thereafter, the Humpel filtering method was used to determine the presence or absence of an abnormality in the signal and then filtered. The statistical results with filtered data were shown. Finally, one cable-stayed bridge and one suspension bridge currently in use were chosen as the target bridges to verify the performance of the developed tool. Signal processing and statistical analysis with the tool were performed. The results are similar to the results reported in the existing work.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.143-160
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• 2023

This study applied the stream physical habitat assessment system to obtain basic information for river restoration and watershed management in high-gradient and mid-gradient streams in the Naeseongcheon basin. The total length of high-gradient and mid-gradient streams in the Naeseongcheon basin is about 273 km, and as a result of the assessment, it was analyzed that suboptimal reach was about 8.2 km, normal reach was 180.3 km, and marginal reach was 84.7 km. In addition, the physical habitat quality of high-gradient streams was analyzed to be normal condition with an average of 106 points (53%), and in particular, the score of channel/hydraulic category, which is the most important for the habitat of aquatic animals, was analyzed to be normal, close to the limit, with an average of 54 points (45%). The physical habitat quality of mid-gradient streams was found to be in normal condition with an average of 90 points (45%), and the score of channel/hydraulic category was in marginal condition with an average of 39 points (32%). Overall, among 165 reaches of high-gradient and mid-gradient streams in the Naeseongcheon basin, 4 reaches (3%) were evaluated as suboptimal, 119 reaches (72%) were normal, and 42 reaches (25%) were considered marginal. These results showed that the physical habitat of Naeseongcheon was significantly disturbed. Disturbance of stream physical habitat in the Naeseongcheon basin occured due to farmland around stream, urbanization, reservoir construction, and river maintenance.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.3
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• pp.236-244
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• 2023

The purpose of this study was to examine the economic feasibility of providing services according to the nationwide expansion of early warning services. The net present value method, one of the cost-benefit analysis methods, was applied to the analysis. As a benefit item that constituted the net present value, the damage reduction amount using crop insurance data and the willingness to pay for the use of early warning services were used. The cost items included system construction and maintenance costs, and text transmission costs. As a result of the analysis, it was found that the nationwide expansion of early warning services had economic feasibility, and its economic effect varied depending on the level of text message use (10 % to 40 %, 10 %p interval) of participating farmers. In the future, the economic effect of early warning services is expected to increase further due to the increase in the number of farmers participating in early warning services and the increase in crop damage caused by climate change. It is necessary to further enhance the economic effect of early warning services by actively utilizing information delivery means through apps or the web as well as text messages.

• Convergence Security Journal
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• v.24 no.3
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• pp.165-171
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• 2024

Due to the IT convergence trend, many industrial domains are developing their own IoT services. With batteries and lightweight devices, IoT could expand into various fields including smart farms, smart environments, and smart energy. Many battery-powered IoT devices are passive in enforcing security techniques to maintain service time. This is because security technologies such as cryptographic operations consume a lot of power, so applying them reduces service maintenance time. This vulnerable IoT device security environment is not stable. In order to provide safe IoT services, security techniques considering battery power consumption are required. In this study, we propose an IoT device authentication technology that minimizes power consumption. The proposed technology is a device authentication function based on the Diffie-Hell man algorithm, and has the advantage that malicious attackers cannot masquerade the device even if salt is leaked during the transmission section. The battery power consumption of the authentication technology proposed in this study and the ID/PW-based authentication technology was compared. As a result, it was confirmed that the authentication technique proposed in this study consumes relatively little power. If the authentication technique proposed in this study is applied to IoT devices, it is expected that a safer IoT security environment can be secured.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.225-266
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• 2018

In 2017, 1,252 cases of damages relief related to air passenger transport service were received by the Korea Consumer Agency, a 0.8% drop from 1,262 cases in 2016, the first decline since 2013. In 2017, 444 cases (35.4%) out of received cases of damages relief in the field of air passenger service received by the Korea Consumer Agency were agreed on, and out of cases that were not agreed on, the most number of 588 cases (47.0%) were concluded due to information provision and counseling, and 186 cases (14.9%) were applied to the mediation of the Consumer Dispute Mediation Committee. Major legislations that contain regulations for the damages relief and disputes resolution of air service consumers include the Aviation Business Act and the Consumer Fundamental Act, etc. The Aviation Business Act provides the establishment and implementation of damage relief procedure and handling plan, and the receiving and handling of request of damage relief by air transport businessman, and the notice of protection standard for air traffic users. The Consumer Fundamental Act provides the establishment and management of the consumer counseling organization, the damage relief by the Korea Consumer Agency, the consumer dispute mediation, and the enactment of the criteria for resolving consumer disputes. The procedures for damages relief of air service consumers include the receiving and handling of damages relief by air transport businessman, the counseling, and receiving and handling of damages relief by the Consumer Counseling Center, the advice of mutual agreement by the Korea Consumer Agency, and the dispute mediation system by the Consumer Dispute Mediation Committee. The current system of damage relief and dispute mediation for air service consumer have the problem in the exemption from obligation of establishment and implementation of damage relief plan by air transport businessman under the Aviation Business Act, the problem in the exemption from liability in case of nonfulfillment and delay of transport by aviation businessman under the criteria for resolving consumer disputes in the aviation sector, and the uppermost limit in procedure progress and completion of consumer dispute mediation under the Consumer Fundamental Act. Therefore, the improvement measurements of the relevant system for proper damage relief and smooth dispute mediation for air service consumer are to be suggested as follows: First is the maintenance of the relevant laws for damage relief of air service consumer. The exemption regulation from obligation of establishment and implementation of damage relief plan by air transport businessman under the Aviation Business Act shall be revised. To enhance the structualization and expertise of the relevant regulation for protection and damage relief of air service consumer, it will be necessary to prepare the separate legislation similar to the US Federal Regulation 14 CFR and EU Regulation EC Regulation 261/2004. Second is the improvement of criteria for resolving air service consumer disputes. For this, it will be necessary to investigate whether the cause of occurrence of exemption reason was force majeure, and distinguish the exemption from liability in case of nonfulfillment and delay of transport by aviation businessman under the criteria for resolving consumer disputes in the aviation sector, and revise the same as exemption reasons regulated under the air transport chapter of the Commercial Act and Montreal Convention 1999, and unify the compensation criteria for the nonfulfillment of transport that the substitute flight was provided and the delay of transport. Third is the reinforcement of information provision for damage relief of air service consumer. Aviation-related government agencies and concerned agencies should cooperate with airlines and airports to provide rapidly and clearly diverse information to the air traffic users, including laws and policies for damages relief of air service consumers. Fourth is the supplement to the effectiveness, etc. of consumer dispute mediation. If there is no sign of acceptance for dispute mediation, it is not fair to regard it as acceptance, therefore it will be necessary to add objection system. And if a dispute resolution is requested to another dispute settlement agency in addition to the Consumer Dispute Mediation Committee, it is excluded from the damage relief package, but it should be allowed for the party to choose a mediation agency. It will be necessary to devise the institutional measures to increase the completion rate of mediation so that the consumer dispute can be resolved efficiently through the mediation. Fifth is the introduction of the air service consumer arbitration system. A measure to supplement the limitations of the consumer dispute mediation system is to introduce the consumer arbitration system, but there are two measurements which are the introduction of the consumer arbitration under the Consumer Fundamental Act and the introduction of the consumer arbitration under the Arbitration Act. The latter measurement is considered to be appropriate. In conclusion, as a policy task, the government should prepare laws and system to enhance the prevention and relief of damages and protection of the rights and interests of air service consumers, and establish and implement the consumer-centric policy for the advancement of air service.

• Journal of the Society of Disaster Information
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• v.11 no.1
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• pp.135-147
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• 2015

Recent underground common utility tunnels are underground facilities for jointly accommodating more than 2 kinds of air-conditioning and heating facilities, vacuum dust collector, information processing cables as well as electricity, telecommunications, waterworks, city gas, sewerage system required when citizens live their daily lives and facilities responsible for the central function of the country but it is difficult to cope with fire accidents quickly and hard to enter into common utility tunnels to extinguish a fire due to toxic gases and smoke generated when various cables are burnt. Thus, in the event of a fire, not only the nerve center of the country is paralyzed such as significant property damage and loss of communication etc. but citizen inconveniences are caused. Therefore, noticing that most fires break out by a short circuit due to electrical works and degradation contact due to combustible cables as the main causes of fires in domestic and foreign common utility tunnels fire cases that have occurred so far, the purpose of this paper is to scientifically analyze the behavior of a fire by producing the model of actual common utility tunnels and reproducing the fire. A fire experiment was conducted in a state that line type fixed temperature detector, fire door, connection deluge set and ventilation equipment are installed in underground common utility tunnels and transmission power distribution cables are coated with fire proof paints in a certain section and heating pipes are fire proof covered. As a result, in the case of Type II, the maximum temperature was measured as $932^{\circ}C$ and line type fixed temperature detector displayed the fire location exactly in the receiver at a constant temperature. And transmission power distribution cables painted with fire proof paints in a certain section, the case of Type III, were found not to be fire resistant and fire proof covered heating pipes to be fire resistant for about 30 minutes. Also, fire simulation was carried out by entering fire load during a real fire test and as a result, the maximum temperature is $943^{\circ}C$, almost identical with $932^{\circ}C$ during a real fire test. Therefore, it is considered that fire behaviour can be predicted by conducting fire simulation only with common utility tunnels fire load and result values of heat release rate, height of the smoke layer, concentration of O2, CO, CO2 etc. obtained by simulation are determined to be applied as the values during a real fire experiment. In the future, it is expected that more reliable information on domestic underground common utility tunnels fire accidents can be provided and it will contribute to construction and maintenance repair effectively and systematically by analyzing and accumulating experimental data on domestic underground common utility tunnels fire accidents built in this study and fire cases continuously every year and complementing laws and regulations and administration manuals etc.

• Economic and Environmental Geology
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• v.56 no.4
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• pp.435-445
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• 2023

A delta is a depositional landform that is formed when sediment transported by a river is deposited in a relatively low-energy environment, such as a lake, sea, or a main channel. Among these, a delta formed at the confluence of rivers has a great importance in river management and research because it has a significant impact on the hydraulic and sedimentological characteristics of the river. Recently, the equilibrium state of the confluence area has been disrupted by large-scale dredging and construction of levees in the Nakdong River. However, due to the natural recovery of the river, the confluence area is returning to its pre-dredging natural state through ongoing sedimentation. The time-series data show that the confluence delta has been steadily growing since the dredging, but once it reaches a certain size, it repeats growth and retreat, and the overall size does not change significantly. In this study, we developed a model to explain the sedimentation-erosion processes in the confluence area based on the assumption that the confluence delta reaches a dynamic equilibrium. The model is based on two fundamental principles: sedimentation due to supply from the tributary and erosion due to the main channel. The erosion coefficient that represents the Nakdong River confluence areas, was obtained using data from the tributaries of the Nakdong River. Sensitivity analyses were conducted using the developed model to understand how the confluence delta responds to changes in the sediment and water discharges of the tributary and the main channel, respectively. We then used annual average discharge of the Nakdong River's tributaries to predict the dynamic equilibrium positions of the confluence deltas. Finally, we conducted a simulation experiment on the development of the Gamcheon-Nakdong River delta using recorded daily discharge. The results showed that even though it is a simple model, it accurately predicted the dynamic equilibrium positions of the confluence deltas in the Nakdong River, including the areas where the delta had not formed, and those where the delta had already formed and predicted the trend of the response of the Gamcheon-Nakdong River delta. However, the actual retreat in the Gamcheon-Nakdong River delta was not captured fully due to errors and limitations in the simplification process. The insights through this study provide basic information on the sediment supply of the Nakdong River through the confluence areas, which can be implemented as a basic model for river maintenance and management.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.195-220
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• 2018

In this study, we conducted an empirical analysis of the factors that affect the change of Bitcoin Closing Price. Previous studies have focused on the security of the block chain system, the economic ripple effects caused by the cryptocurrency, legal implications and the acceptance to consumer about cryptocurrency. In various area, cryptocurrency was studied and many researcher and people including government, regardless of country, try to utilize cryptocurrency and applicate to its technology. Despite of rapid and dramatic change of cryptocurrencies' price and growth of its effects, empirical study of the factors affecting the price change of cryptocurrency was lack. There were only a few limited studies, business reports and short working paper. Therefore, it is necessary to determine what factors effect on the change of closing Bitcoin price. For analysis, hypotheses were constructed from three dimensions of consumer, industry, and macroeconomics for analysis, and time series data were collected for variables of each dimension. Consumer variables consist of search traffic of Bitcoin, search traffic of bitcoin ban, search traffic of ransomware and search traffic of war. Industry variables were composed GPU vendors' stock price and memory vendors' stock price. Macro-economy variables were contemplated such as U.S. dollar index futures, FOMC policy interest rates, WTI crude oil price. Using above variables, we did times series regression analysis to find relationship between those variables and change of Bitcoin Closing Price. Before the regression analysis to confirm the relationship between change of Bitcoin Closing Price and the other variables, we performed the Unit-root test to verifying the stationary of time series data to avoid spurious regression. Then, using a stationary data, we did the regression analysis. As a result of the analysis, we found that the change of Bitcoin Closing Price has negative effects with search traffic of 'Bitcoin Ban' and US dollar index futures, while change of GPU vendors' stock price and change of WTI crude oil price showed positive effects. In case of 'Bitcoin Ban', it is directly determining the maintenance or abolition of Bitcoin trade, that's why consumer reacted sensitively and effected on change of Bitcoin Closing Price. GPU is raw material of Bitcoin mining. Generally, increasing of companies' stock price means the growth of the sales of those companies' products and services. GPU's demands increases are indirectly reflected to the GPU vendors' stock price. Making an interpretation, a rise in prices of GPU has put a crimp on the mining of Bitcoin. Consequently, GPU vendors' stock price effects on change of Bitcoin Closing Price. And we confirmed U.S. dollar index futures moved in the opposite direction with change of Bitcoin Closing Price. It moved like Gold. Gold was considered as a safe asset to consumers and it means consumer think that Bitcoin is a safe asset. On the other hand, WTI oil price went Bitcoin Closing Price's way. It implies that Bitcoin are regarded to investment asset like raw materials market's product. The variables that were not significant in the analysis were search traffic of bitcoin, search traffic of ransomware, search traffic of war, memory vendor's stock price, FOMC policy interest rates. In search traffic of bitcoin, we judged that interest in Bitcoin did not lead to purchase of Bitcoin. It means search traffic of Bitcoin didn't reflect all of Bitcoin's demand. So, it implies there are some factors that regulate and mediate the Bitcoin purchase. In search traffic of ransomware, it is hard to say concern of ransomware determined the whole Bitcoin demand. Because only a few people damaged by ransomware and the percentage of hackers requiring Bitcoins was low. Also, its information security problem is events not continuous issues. Search traffic of war was not significant. Like stock market, generally it has negative in relation to war, but exceptional case like Gulf war, it moves stakeholders' profits and environment. We think that this is the same case. In memory vendor stock price, this is because memory vendors' flagship products were not VRAM which is essential for Bitcoin supply. In FOMC policy interest rates, when the interest rate is low, the surplus capital is invested in securities such as stocks. But Bitcoin' price fluctuation was large so it is not recognized as an attractive commodity to the consumers. In addition, unlike the stock market, Bitcoin doesn't have any safety policy such as Circuit breakers and Sidecar. Through this study, we verified what factors effect on change of Bitcoin Closing Price, and interpreted why such change happened. In addition, establishing the characteristics of Bitcoin as a safe asset and investment asset, we provide a guide how consumer, financial institution and government organization approach to the cryptocurrency. Moreover, corroborating the factors affecting change of Bitcoin Closing Price, researcher will get some clue and qualification which factors have to be considered in hereafter cryptocurrency study.