• Geomechanics and Engineering
• /
• v.21 no.3
• /
• pp.301-313
• /
• 2020

In the process of mining closely spaced coal seams, the problem of roadway arrangement in lower coal seams has long been a concern. By means of mechanical model calculation and numerical simulation postprocessing, the distribution of the stress deviator below the floor of a goaf and the evolution of the stress deviator in the vertical and horizontal directions are studied under the influence of horizontal stress. The results of this theoretical study and numerical simulation show that the stress deviator decreases exponentially with increasing depth from the floor below the coal side. With the increase in the horizontal stress coefficient λ, the stress deviator concentration area shifts. The stress deviator is concentrated within 10 m below the goaf and 15 m laterally from the coal side; thus, the magnitude of the surrounding rock stress deviator should be considered when planning the construction of a roadway in this area.

• Geomechanics and Engineering
• /
• v.18 no.6
• /
• pp.661-668
• /
• 2019

Seismic vulnerability assessment is a useful tool for rational safety analysis and planning of large and complex structural systems; it can deal with the effects of uncertainties on the performance of significant structural systems. In this study, an efficient dynamic reliability approach, probability density evolution methodology (PDEM), is proposed for seismic vulnerability analysis of earth dams. The PDEM provides the failure probability of different limit states for various levels of ground motion intensity as well as the mean value, standard deviation and probability density function of the performance metric of the earth dam. Combining the seismic reliability with three different performance levels related to the displacement of the earth dam, the seismic fragility curves are constructed without them being limited to a specific functional form. Furthermore, considering the seismic fragility analysis is a significant procedure in the seismic probabilistic risk assessment of structures, the seismic vulnerability results obtained by the dynamic reliability approach are combined with the results of probabilistic seismic hazard and seismic loss analysis to present and address the PDEM-based seismic probabilistic risk assessment framework by a simulated case study of an earth dam.

• Journal of Conservation Science
• /
• v.35 no.1
• /
• pp.51-60
• /
• 2019

This paper provides quantitative data that describes the evolution of the air quality in the Whale and Sea Museum, located in the Iwate prefecture, collected after the 2011 Great East Japan Earthquake and tsunami. The museum was damaged significantly by the disaster, and restoration works continued for over six years. The air quality in the temporary storage facility and museum was monitored during the rehabilitation process. Evaluation of air quality is carried out by gas chromatography- mass spectrometry, ion chromatography and high-performance liquid chromatography. The results showed that the characteristics of the chemical components differed depending on the measurement locations inside the building. The museum atmosphere tended to be alkaline as the airtightness increased because of the maintenance works at the entrance. It was also determined that it was necessary to study the intake/exhaust routes and to clean them according to the contamination degree. In Japan, there are recommended museum air quality standards for acetic acid, formic acid, alkali, and aldehydes. The results indicated that these standards should not be used as a reference for damaged museums. Furthermore, at the temporary storage facilities for to store the collections during the rehabilitation of the museum, solvents such as ethyl benzene, toluene, and xylene are initially abundant, although they can be reduced by ventilation, while other components such as 2E1H was confirmed in this case are likely to remain.

• Structural Engineering and Mechanics
• /
• v.71 no.6
• /
• pp.699-712
• /
• 2019

The reinforced concrete lining of hydraulic pressure tunnels tends to crack under high inner water pressure (IWP), which results in the inner water exosmosis along cracks and involves typical hydro-mechanical interaction. This study aims at the development, validation and application of an indirect-coupled method to simulate the lining cracking process. Based on the concrete damage plasticity (CDP) model, the utility routine GETVRM and the user subroutine USDFLD in the finite element code ABAQUS is employed to calculate and adjust the secondary hydraulic conductivity according to the material damage and the plastic volume strain. The friction-contact method (FCM) is introduced to track the lining-rock interface behavior. Compared with the traditional node-shared method (NSM) model, the FCM model is more feasible to simulate the lining cracking process. The number of cracks and the reinforcement stress can be significantly reduced, which matches well with the observed results in engineering practices. Moreover, the damage evolution of reinforced concrete lining can be effectively slowed down. This numerical method provides an insight into the cracking process of reinforced concrete lining in hydraulic pressure tunnels.

• International conference on construction engineering and project management
• /
• 2013.01a
• /
• pp.386-389
• /
• 2013

Under climate change and urbanization, rainwater harvesting (RWH) systems are emerging as an alternative source of water supply because of growing concern about water sustainability. RWH systems can satisfy the various watering needs and provide the environmental benefits of lessening the damages from flood, drought, and runoff. The economic success of a RWH system is vitally concerned with the determination of the design capacity of storage tank to be built in the system. The design capacity is determined by the factors of average annual rainfall, period of water scarcity, and water price during the whole life-cycles. Despite the high uncertainties inherent in these factors, the current engineering design of RWH system construction often assumes that storage tanks should be built all at once. This assumption implicitly ignores the managerial flexibility in responds to the future as new information comes out-the right to build storage tanks stage by stage depending on the evolution of demand. This study evaluates the value of a multistage storage tank construction using a real option approach. A case study involving a typical RWH system construction in Jeonju, the Republic of Korea is conducted. The managerial flexibility obtained from the real option perspective allows engineers to develop investment strategies to better cope with the issue of water sustainability.

• Restorative Dentistry and Endodontics
• /
• v.49 no.1
• /
• pp.1.1-1.18
• /
• 2024

The implementation of imaging methods that enable sensitive and specific observation of anatomical structures has been a constant in the evolution of endodontic therapy. Cone-beam computed tomography (CBCT) enables 3-dimensional (3D) spatial anatomical navigation in the 3 volumetric planes (sagittal, coronal and axial) which translates into great accuracy for the identification of endodontic pathologies/conditions. CBCT interpretation consists of 2 main components: (i) the generation of specific tasks of the image and (ii) the subsequent interpretation report. A systematic and reproducible method to review CBCT scans can improve the accuracy of the interpretation process, translating into greater precision in terms of diagnosis and planning of endodontic clinical procedures. MEDLINE (PubMed), Web of Science, Google Scholar, Embase and Scopus were searched from inception to March 2023. This narrative review addresses the theoretical concepts, elements of interpretation and applications of the CBCT scan in endodontics. In addition, the contents and rationale for reporting 3D endodontic imaging are discussed.

• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.529-538
• /
• 2015

This paper was intended to empirically identify problems with recreational sea fishing park facilities installed to help reinvigorate local economy of fishing villages in order to mitigate shortage of fishing facilities amid an increase in sea fishers and spur evolution of sea fishing into a marine leisure activity, on which basis this researcher presented direction for facility planning which is deemed necessary to map out the plan for sea fishing parks, along with measures designed to improve sea fishing park facilities. To analyze the problems related to sea fishing park facilities, we conducted a survey on facility operations involving 9 sea fishing parks and 2 sea ranches and had an investigative interview with facility manager. Moreover, a survey was conducted of fishers in 25 sea fishing places, including sea fishing park, fishing experience village, etc., in order to investigate their demand for facilities. The results of survey suggested that there was a significant demand for expansion of amenities such as safety facilities, toilets, lounge facilities, etc., which can accommodate the increase in the number of people fishing with family. Furthermore, the results showed that there was a huge demand for introduction of facilities aiding leisure activities in addition to facilities for fishing activities including education facilities such as fishing site at the corner exclusive for beginners, experiential facilities, camping site, seaside park, promenade, etc. Thus, sea fishing park should be the complex leisure space with a focus on fishing activities and requires facility configuration and facility planning suited to activity requirements within fishing park.

• Korean Journal of Heritage: History & Science
• /
• v.52 no.3
• /
• pp.94-111
• /
• 2019

This study aims to examine the evolutionary process of the protection-management system for historic monuments and their surroundings in France over one-hundred years. Because France and Korea shared policies and institutions regarding the management of historical monuments (cultural property) along with their surroundings, it is necessary to explore the French experience from a comparative perspective. In France, historical monuments began to be recognized as national heritage according to "the 1913 law" which has continued to evolve for more than one hundred years. In the beginning, a historical monument was preserved as a single building unit; however, since 1943, a new policy has been implemented to preserve sets of historical monuments along with their perimeters of protection zones. Moreover, since 1980, in the context of decentralization, local authorities have been given more roles and autonomy concerning the management of historic monuments and their surroundings. Local authorities have played a key role in the protection-management of historic monuments and their surroundings, and have become more active in the conservation of their architectural heritage, including historic monuments. The central government, however, remains as the headquarters whose rigorous policies provide a solid foundation for the decentralized management system of architectural and cultural heritage, including historic monuments. The final goal in the evolutionary process, then, targets the effective and harmonious integration of the protection-management system for historic monuments and their surroundings into urban and regional planning.

• Korea Science and Art Forum
• /
• v.25
• /
• pp.103-118
• /
• 2016

Due to the rapid development of ICT, corporate business models quickly changed and because of the radical growth of IT technology, sequential or gradual survival has become difficult. Internet-based new businesses such as IT service companies are seeking for new convergence business models that have not existed before to create business models that are more competitive, but the economic efficiency of business models that were successful in the past is wearing off. Yet, as reaching the critical point where the platform value becomes extremely high for platforms via the Internet is happening at a much higher speed than before, platform-ization has become a very important condition for rapid business expansion for all kinds of businesses. This study analyzes the necessity of establishing platform business models in IT service planning and identifies their characteristics through case analyses of platform business models. The results derived features First, there is a need to ensure sufficient buyers and sellers, and second, platform business model should provide customers with distinctive value of the only platforms are generating. third, the common interests between platform-driven company and a partner, participants Should be existing. Fourthly, by expanding base of participants and upgrades, expansion of adjacent areas we must have a continuous scalability and evolution must be sustainable. While it is expected that the identified characteristics will cause tremendous impacts to the establishment of platform business models and to the graphing of service planning, we also look forward to this study serving as the starting point for the establishment of theories of profit models for platform businesses, which were not mentioned in the study, so that planners responsible for platform-based IT service planning will spend less time and draw bigger schemes in building planning drafts.

• Cartoon and Animation Studies
• /
• s.39
• /
• pp.261-295
• /
• 2015

Cyber singer appeared in the late 1990s has disappeared briefly appeared. although a few attempts in the 2000s, it did not show significant successes. cyber singer was born thanks to the technical development of the IT industry and the emergence of an idol training system in the music industry. It was developed by Vocaloid 'Seeyou' starting from 'Adam'. cyber singer that differenatiated typical digital characters in a cartoon or game may be subject to idolize to the music as a medium. They also feature forming a plurality of fandom. therefore, such attempts and repeated failures, this could be considered a fashion, but it flew content creation and ongoing attempts to take advantage of the new media, such as Vocaloid can see that there are expectations for a true Cyber-born singer. Early-Cyber singer is made only resemble human appearance, but 'Sciart' and 'Seeyou' has been evolving to becoming more like the human capabilities. in this paper, stylized cyber singer had disappeared in the past in the process of developing the technology to evolve into own artificial life does not end in failure cases, gradually led to a change in public perceptions of the image look looking machine was an attempt in that sense. With the direction of the evolution of the mechanical function to obtain a human, fun and human exchanges and mutual feelings. And it is equipped with an artificial life form that evolved with it only in appearance and function. in order to support this logic, I refer to the study of the coevolution of man and machine at every Bruce Mazlish. And, I have analyzed the evolution of cyber singer Bruce research from the perspective of the development process since the late 1990s, the planning of the eight singers who have appeared and design of the cyber character and important voices to be evaluated as a singer (vocal). The machine has been evolving coevolution with humans. cyber singer ambivalent development targets are recognized, but strive to become the new artificial creatures of horror idea of human desire and death continues. therefore, the new Cyber-organisms are likely to be the same style as 'Seeyou'. because, cartoon forms and whirring voice may not be in the form of a signifier is the real human desires, but this is because the contemporary public's desire to be desired and the technical development of this type can be created at the point where the cross-signifier.