• Geomechanics and Engineering
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• v.37 no.6
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• pp.599-614
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• 2024

To evaluate the safety status of deteriorated segments in a submarine shield tunnel during its service life, a seepage model was established based on a cross-sea shield tunnel project. This model was used to study the migration patterns of erosive ions within the shield segments. Based on these laws, the degree of deterioration of the segments was determined. Using the derived analytical solution, the internal forces within the segments were calculated. Lastly, by applying the formula for calculating safety factors, the variation trends in the safety factors of segments with different degrees of deterioration were obtained. The findings demonstrate that corrosive seawater presents the evolution characteristics of continuous seepage from the outside to the inside of the tunnel. The nearby seepage field shows locally concentrated characteristics when there is leakage at the joint, which causes the seepage field's depth and scope to significantly increase. The chlorine ion content decreases gradually with the increase of the distance from the outer surface of the tunnel. The penetration of erosion ions in the segment is facilitated by the presence of water pressure. The ion content of the entire ring segment lining structure is related in the following order: vault < haunch < springing. The difference in the segment's rate of increase in chlorine ion content decreases as service time increases. Based on the analytical solution calculation, the segment's safety factor drops more when the joint leaks than when its intact, and the change rate between the two states exhibits a general downward trend. The safety factor shows a similar change rule at different water depths and continuously decreases at the same segment position as the water depth increases. The three phases of "sudden drop-rise-stability" are represented by a "spoon-shaped" change rule on the safety factor's change curve. The issue of the poor applicability of indicators in earlier studies is resolved by the analytical solution, which only requires determining the loss degree of the segment lining's effective bearing thickness to calculate the safety factor of any cross-section of the shield tunnel. The analytical solution's computation results, however, have some safety margins and are cautious. The process of establishing the evaluation model indicates that the secondary lining made of molded concrete can also have its safety status assessed using the analytical solution. It is very important for the safe operation of the tunnel and the safety of people's property and has a wide range of applications.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.351-352
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• 2004

• Journal of the Korean Society of Safety
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• v.38 no.1
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• pp.87-92
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• 2023

The number of unmanned light rail train operators is continuously increasing in Korea. In a failure event during an operation due to the nature of the unmanned operation, recovery is performed based on the remote control. However, if remote recovery is not feasible, safety personnel arrive at the train to resume the train operation. There are regulations on safety personnel and the suspension time of the train operation. However, there is currently no rule for safety personnel deployment. Currently, railway operating organizations operate in three scenarios: safety personnel on board trains, stationed at stations, and deployed at major stations. Four major factors influence the downtime for each emergency response scenario. However, these four influencing factors vary too much to predict results with simple calculations. In this study, four influencing factors were considered as random variables with high uncertainty. In addition, the Monte Carlo method was applied to each scenario for the safety personnel deployment to predict train service downtime. This study found a 17% difference in train service suspension by safety personnel deployment scenario. The results of this study can be used in setting service goals, such as standards for future safety personnel placement and frequency of service interruptions.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.4
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• pp.11-20
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• 2022

Currently, the operation rule of agricultural reservoirs in case of drought events follows the drought forecast warning standard of agricultural water supply. However, it is difficult to preemptively manage drought in individual reservoirs because drought forecasting standards are set according to average reservoir storage ratio such as 70%, 60%, 50%, and 40%. The equal standards based on average water level across the country could not reflect the actual drought situation in the region. In this study, we proposed the improvement of drought operation rule for agricultural reservoirs based on the percentile approach using past water level of each reservoir. The percentile approach is applied to monitor drought conditions and determine drought criteria in the U.S. Drought Monitoring (USDM). We applied the drought operation rule to reservoir storage rate in extreme 2017 spring drought year, the one of the most climatologically driest spring seasons over the 1961-2021 period of record. We counted frequency of each drought criteria which are existing and developed operation rules to compare drought operation rule determining the actual drought conditions during 2016-2017. As a result of comparing the current standard and the percentile standard with SPI6, the percentile standard showed severe-level when SPI6 showed severe drought condition, but the current standard fell short of the results. Results can be used to improve the drought operation criteria of drought events that better reflects the actual drought conditions in agricultural reservoirs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.53-60
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• 2011

In this study, the priority was assessed and the compensation relationships were analyzed with regard to the issue of port development with conflicts among decision makers. First, the assessment factors were selected by the relevant literatures on port development, and fuzzy structure modeling was used to select assessment factors via structuralization analysis. Second, the local residents, port users, and local government were chosen as the main port-development related entities, and the analytic hierarchy process was used to calculate the total assessment value. Third, the justice based on majority power rule method was used as an assessment method that would minimize the amount of complaints according to the total assessment results and the alternative selection when a partnership was formed among the assessment entities. Moreover, the compensation issue according to the alternative selection was quantified, and the compensation relationships were analyzed. As a result, it was found that port development in Busan must be the top priority in terms of port development in South Korea, that awareness of environmental issues must be promoted among the port users, and that the local governments must promote environmental incentive policies for Environment-friendly port development.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.141-165
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• 1999

The Customs Act provides for a general rule all goods entering Korea shall be subject to customs duties as set in the customs tariff schedules as other fees and taxes determined except those excluded by virtue of the Customs Act or intentional agreements. Importation begins from the time carrying vessel or aircraft enters Korea territorial jurisdiction with the intention to unload the same until the time the goods are released or withdrawn from the customhouse upon payment of the appropriate duties. Imported articles may be categorized into prohibited importations, dutiable importations and conditionally free importation. Some other articles are qualifiedly prohibited, meaning they can enter the country after compliance with certain conditions. If there is any conduct violating these act, criminal sanctions may be imposed for the prevention and suppression of smuggling and other frauds, and the enforcement of tariff and customs act. As a result importers who intentionally violates Korea Customs Act may be subject to criminal prosecution. Many major provisions of customs act have imposed severe sanctions for customs crimes in comparison with other crimes due to general rule of criminal law. There is a great deal of activity in Pusan area relating to smuggling of narcotics and prohibited drugs, obscene articles and weapons. On one side, criminals who seek to profit by narcotics or drug threaten public health and human environment, On other side, weapon smuggling is a significant threat to our national security. However the studies on customs crime and customs act have not been viewed. Thus this Article overviews especially the customs crime and criminal sanction focused on domestic customs act.

• Journal of the Korea Safety Management & Science
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• v.4 no.2
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• pp.71-81
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• 2002

Today's environment of enterprise is changing. They have to face customer' demands with the right product, the right service and supply them at the right time. And also cut down logistics and inventory cost and bring up the profit as much as they can. This means the change of putting enterprise first in importance to putting customer first importance. therefore to correspond to customer's demand, shorting lead time is becoming a essential condition. The answer to this changes of environment is supply chain management. In the Supply chain, The ATP function doesn't only give customers to conformation of delivery. It can be used by the core function with ATP rule that can reconcile supplies and demands on the supply chain. Therefore We can be acquire the conformation about on the due date of supplier by using the ATP function of management about real and concurrent access on the supply chain, also decide the affect about product availability due to forecasting or customer's orders through the ATP. In this paper, It consolidates the necessity on a CTP and analyzes data which is concerned of ATP. Under the these environments, defines the ATP rule that can improve the customer value and data flow related the LTV(Life Time Value) and builds on a algorithm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.3
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• pp.537-552
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• 2024

Domestic nuclear power plants operate under the establishment of the "Information System Security Regulations" in accordance with the Nuclear Safety Act, introducing and implementing a cybersecurity system that encompasses organizational structure as well as technical, operational, and managerial security measures for assets. Despite attempts such as phased approaches and alternative measures for physical protection systems, the reduction in managed items has not been achieved, leading to an increased burden on security capabilities due to limited manpower at the site. In the main text, an analysis is conducted on Type A1 assets performing nuclear safety functions using Maintenance Rules (MR) and EPRI Technical Assessment Methodology (TAM) from both a maintenance perspective and considering device characteristics. Through this analysis, approaches to re-evaluate the impact of cyber intrusions on asset functionality are proposed.

• Journal of the Korean Society of Safety
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• v.9 no.1
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• pp.134-139
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• 1994

In order to assess the level of atmospheric pollution and to contribute the hearth improvement of residents in Taejon city, the authors were measured the concentration of air pollutants(CO, SO$_2$, NO$_2$, TSP, Pb, Cd, Cr) at three places of the control road in Taejon. The investigative research performed bimonthly from May 1993 to September 1993, and the places were the underground shopping stores of Taejon station, Dongyang department store and provincial goverment areas. The results of statistical analysis are as followings. \circled1CO :0.569~0.966ppm \circled2SO$_2$：0.084~0.170ppm \circled3NO$_2$:0.0045~0.022ppm \circled4TSP：249~299$\mu\textrm{g}$/㎥. \circled5Pb :0.366~1.157$\mu\textrm{g}$/㎥. \circled6Cd：0.016~0.025$\mu\textrm{g}$/㎥. \circled7 Cr : 0.198 ~0.290$\mu\textrm{g}$/㎥. The mean concentration of SO$_2$in Dongyang department store area was 0.17ppm, and it exceeded the ambient air quality standard by 0.02ppm. The concentration of TSP was higher than a standing rule of public hygiene, and it was very near to a standing rule of environmental preservation. The standing rule of indoor air pollution in underground shopping store have two different laws, the public hygiene and the environmental preservation. Therefore, it was difficult to judge what to do in such circumstance. In regarding to the laws, an environmental standard for air pollution in the underground space must unify into the standard of public hygiene.

• Korean Security Journal
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• no.34
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• pp.233-258
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• 2013

In the early days of the Goryeo Dynasty, the royal guard was comprised of the central regular army in the 2-gun-6-wi system, and Nasungeomgun was in charge of the security inside the palace. However, the military system became disorganized during the period of military rule and the royal guard had to rely on military subjects. The military officials suppressed the civil ministers centering on Jungbang, the guarding organization close to the King to incapacitate the royal authority and control the state affairs. When the rule of the three leaders of the military rule became short-lived and Dae-seung Gyeong is raised to the ruler, he organized a do-or-die squad comprised of a hundred and more people for his personal safety, and this became the first dobang. Dobang was disassembled after Dae-seung Gyeong died of disease, but under the rule of Chung-heon Choe, Dae-seung Gyeong's dobang was revived and reinforced into 'Yukbeon Dobang' to provide the ruler with personal protection and intensify the ruling system, and it was quite a large organization with more refined system. Yukbeon Dobang was expanded and reinforced into Naeoedobang under the rule of Woo Choe, the son of Chung-heon Choe, and it was enhanced even more into Dobang Samsipyukbeon System under the rule of the grandson, Hang Choe. Dobang can be considered as the guard organization in modern sense, and it collected information and surveyed the area where guarding is required and house troops that belonged to Naedobang eliminated the risks that may follow afterwards to make assurance doubly sure for guarding. The Choe's regime established Mabyeolcho as a private guard organization in addition to dobang, and this formed the cavalry and infantry units with dobang. Yabyeolcho organized by Woo Choe in the reign of King Gojong was divided into Joabyeolcho and Ubyeolcho, and later Sineuigun was integrated with them to form Sambyeolcho. Originally, Yabyeolcho was established under the rule of Woo Choe to prevent crime in the evening, but after Sineuigun was organized with the ones who were captured by Mongolian army but escaped, in other words when Sambyeolcho was organized, the organization displayed much broader influence by covering military and police affairs as well as punishment and imprisonment. The guarding organization during the Period of Military Rule in the Goryeo Dynasty did not have strict distinction between official guard and personal guard. The private guard in modern days which is the equivalent of personal guard is characterized by its commerciality, however, house troops and the members of dobang did not seem to pursued profit. The guard organization during the period of military rule started from dobang which was organized for personal safety but gradually developed publicness through the participation of civil ministers and expansion, and later it played the pivotal role for social security serving official purpose up to the level where the distinction between official and private activities was blurred during the period of Sambyeolcho.