• Journal of Construction Engineering and Project Management
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• v.6 no.2
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• pp.30-39
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• 2016

This research presents the development of a self-governing mobile robot navigation system for indoor construction applications. This self-governing robot navigation system integrated robot control units, various positioning techniques including a dead-reckoning system, a UWB platform and motion sensors, with a BIM path planner solution. Various algorithms and error correction methods have been tested for all the employed sensors and other components to improve the positioning and navigation capability of the system. The research demonstrated that the path planner utilizing a BIM model as a navigation site map could effectively extract an efficient path for the robot, and could be executed in a real-time application for construction environments. Several navigation strategies with a mobile robot were tested with various combinations of localization sensors including wheel encoders, sonar/infrared/thermal proximity sensors, motion sensors, a digital compass, and UWB. The system successfully demonstrated the ability to plan an efficient path for robot's movement and properly navigate through the planned path to reach the specified destination in a complex indoor construction site. The findings can be adopted to several potential construction or manufacturing applications such as robotic material delivery, inspection, and onsite security.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.12
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• pp.5759-5779
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• 2017

As the main means to cope with the stubborn problem of drunk driving, the inspection of drunk driving has already been paid more attention and thus reinforced. In this paper, we model this scenario as a Stackelberg game, where the police department (called defender) allocates resources dynamically in terms of the traffic situation on the traffic network to arrest drink drivers and drivers who drink (called attacker), whether choosing drunk driving or designated driving service, expect to minimize their cost for given travel routes. However, with the number of resources are limited, our goal is to calculate the optimal resource allocation strategy for the defender. Therefore, first, we provide an effective approach (named OISDD) to fulfill our goal, i.e., generate the optimal strategy to inspect drunk driving. Second, we apply OISDD to directed graphs (which are abstracted from Dalian traffic network) to analyze and test its correctness and rationality. The experimental results show that OISDD is feasible and efficient.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.105-112
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• 2014

The utilization of Wireless Ad Hoc Network which can build easily network using wireless device in difficult situation to build network is very good. However, it has security threat element because it transfers data by only forwarding of wireless devices. The measures against this should be prepared because damage by especially routing attack can affect the entire network. It is hard to distinguish malicious node and normal node among nodes composing network and it is not easy also to detect routing attack and respond to this. In this paper, we propose new method which detect routing attack and can respond to this. The amount of traffic in all nodes is measured periodically to judge the presence or absence of attack node on the path set. The technique that hides inspection packet to suspected node and transmits is used in order to detect accurately attack node in the path occurred attack. The experiment is performed by comparing SRAODA and SEAODV technique to evaluate performance of the proposed technique and the excellent performance can be confirmed.

• Journal of Information Management
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• v.41 no.4
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• pp.205-226
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• 2010

Assuring that the integrity of digital contents is reliably maintained is an important component of long-term digital preservation. The purpose of this study was to examine and analysis the best practices of digital preservation policy and provide the basis theory for establishing a preservation policy for maintaining the integrity of digital contents. In order to achieve the purpose of the study, we examined the digital archiving practices for maintaining the integrity of digital contents. Especially, we focused on the storage media and file formats, the media and format conversion, disaster prevention and recovery, management and handling, inspection and monitoring, and security policies.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.183-188
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• 2020

As the number of kids cafes, one of the children's playgrounds, is increasing rapidly, safety accidents in the kids cafe are also increasing rapidly. The facility is also increasing as the need increases, but it is spreading without ensuring safety. In particular, the Ministry of Public Administration and Security for children's play facilities in the kids cafe, and the Ministry of Culture, Sports and Tourism for organic organizations are divided into different departments, so it is not easy for local governments to manage and supervise the actual business, and there are safety blind spots. Kids cafes have changed rapidly according to needs of children and guardians who are users, and there are many problems associated with them. Therefore, we identified problems that may arise due to insufficient safety management systems for kids cafes, investigated the safety management related to kids cafes in advanced countries, and compared and analysed them with domestic systems. As a result of the research, we proposed a safety management reinforcement system, and we hope to contribute to the reduction and prevention of kids café safety accidents.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.837-847
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• 2007

The study focused on the evaluation of maintenance management strategies used in public hospital buildings in Lagos state. It also assessed the labour composition for maintenance operations. In achieving these objectives, opinions of maintenance officers of ten (10) different hospitals in different local government areas of the state were sampled through well structured questionnaires. The data collected were analyzed using descriptive and inferential statistics. From the analysis, the study revealed that majority of those public hospitals do not have specific budget for maintenance programmes, maintenance policies, maintenance log book and maintenance manual to guide the operatives. About 98% of them do not understand the type of maintenance strategy being used for their maintenance operations. 78% of the maintenance work are only executed when there is a breakdown or in response to user's request. For labour composition, the cleaning of interior and exterior of the building, inspection of building elements, repairs and replacements of building elements are mainly carried out by in-house staff, while the repair and replacement of equipment is by outsourcing. The study also revealed that using in- house staff, reduces costs and provides a higher security while outsourcing provides more flexibility in staffing reduces equipment expenditures and provide better access to special skills. The study recommended proactive measures to provide necessary training and support for maintenance staff and users of these facilities and a means of securing sufficient funds for maintenance programmes.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.3
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• pp.213-220
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• 2023

Face recognition is a very important process in video monitoring and is a type of biometric technology. It is mainly used for identification and security purposes, such as ID cards, licenses, and passports. The recognition process has many variables and is complex, so development has been slow. In this paper, we proposed a face recognition method using CNN, which has been re-examined due to the recent development of computers and algorithms, and compared with the feature comparison method, which is an existing face recognition algorithm, to verify performance. The proposed face search method is divided into a face region extraction step and a learning step. For learning, face images were standardized to 50×50 pixels, and learning was conducted while minimizing unnecessary nodes. In this paper, convolution and polling-based techniques, which are one of the deep learning technologies, were used for learning, and 1,000 face images were randomly selected from among 7,000 images of Caltech, and as a result of inspection, the final recognition rate was 98%.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3506-3513
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• 2023

In this paper, we demonstrate the neutron attenuation of dry cask shielding materials using the S670e helium-4 detector manufactured by Arktis Radiation Ltd. In particular, two materials expected to be applied to the TN-32 dry cask manufactured by ORANO Korea and KORAD-21 by the Korea Radioactive Waste Agency (KORAD) were utilized. The measured neutron attenuation was compared with our Monte Carlo N-Particle Transport simulation results, and the difference is given as the root mean square (RMS). For the fast neutron case, a rapid decline in neutron counts was observed as a function of increasing material thickness, exhibiting an exponential relationship. The discrepancy between the experimentally acquired data and simulation results for the fast neutron was maintained within a 2.3% RMS. In contrast, the observed thermal neutron count demonstrated an initial rise, attained a maximum value, and exhibited an exponential decline as a function of increasing thickness. In particular, the discrepancy between the measured and simulated peak locations for thermal neutrons displayed an RMS deviation of approximately 17.3-22.4%. Finally, the results suggest that a minimum thickness of 5 cm for Li-6 is necessary to achieve a sufficiently significant cross-section, effectively capturing incoming thermal neutrons within the dry cask.

• Journal of Radiation Industry
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• v.17 no.4
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• pp.443-449
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• 2023

KAERI(Korea Atomic Energy Research Institute) is conducting research and development of large-scale radiation generators and the latest radiation measuring instruments. In particular, research and development of security screening equipment using an electron beam accelerator and a neutron generator is in progress recently. Globally, 20 ft containers are used to transport imports and exports, and electron beam accelerators are radiation sources to measure the shape of the material inside the container during customs inspections in each country. KAERI is developing a device that can use an electron beam accelerator and a neutron generator sequentially to grasp the shape of various materials as well as the location of the internal target material. In this study, when using the neutron generator, the radiation dose and the degree of activation by neutron for the facility and surrounding environment, facility equipment were simulated using MCNP and FISPACT code. As a result, the shielding structures inside and outside the radiation control area were satisfactory to the reference level established conservatively based on the Korean Nuclear Act.

• Korean Security Journal
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• no.55
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• pp.117-141
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• 2018

Police crime statistics report that residential housing such as apartment, low rise, detached houses is the second most vulnerable to crime, which is closely followed by the number of street crimes. Also residential houses are often exposed to quality-of-life crime, e.g burglary. It threatens the basic human rights of house residents in terms of safety and comfort within the urban living environment. This study examines related precedent studies regarding the vulnerability of residential housing including studios, multi-family housing from the viewpoint of crime prevention through environment design(CPTED), extracted the elements and items suitable for the safety of residential facilities and the certification evaluation indicators and check items to be the basis for the checklist are derived. Based on these evaluation indicators and inspection items, we conducted on-site surveys of residential facilities in three areas of Seoul, Yongin and Asan, and the final draft of the checklist was revised based on the results of the field survey. There are 43 items on the 7 fields of evaluation in the final version of checklist, 11 items in the management and operation, 20 items in the surveillance, 7 items in the access control, 1 item in the territoriality, 2 items in the activity support, and 2 items in the security and safety facilities. In addition, various points of interest were added to allow the administrator of the residential facility to earn points for special measures taken for safety. This checklist can be appropriately modified and utilized in consideration of the characteristics of each facility. Korean national police agency has CPOs to check the residential facilities in their jurisdiction using checklists and to certify excellent facilities with high level of safety.