• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.125-133
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• 2011

According to proliferation of mobile devices, security threats have been continuously increased such as illegal or unintentional file transmission of important data to an external mass-storage device. Therefore, we propose a protection method to prohibit an illegal outflow to this device and implement this method. This method extracts signatures from random locations of important file and uses them to detect and block illegal file transmission. To get signatures, a target file is divided by extracting window size and more than one signatures are extracted in this area. To effective signature sampling, various extraction ways such as full, binomial distribution-based and dynamic sampling are implemented and evaluated. The proposed method has some advantages. The one is that an attacker cannot easily predict the signature and its extraction location. The other is that it doesn't need to modify original data to protect it. With the help of these advantages, we can say that this method can increase efficiency of easy-to-use and it is a proper way leakage prevention in a mobile device.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.551-564
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• 2021

The use of clean energy based on the hydrogen economy is increasing rapidly due to the greenhouse gas reduction policies and the increase in the need for hydrogen. Currently, South Korea government have been considering a plan to construct hydrogen refueling stations at expressway service area for the purpose of supplying hydrogen vehicles. In the case of a hydrogen refueling stations, a quantitative risk assessment (QRA) must be performed because it includs and uses a high pressurized hydrogen storage tank. In this study, QRA was conducted using societal risk and F-N curve by the consequence assessment (CA) of jet fire and explosion according to the population density, capacity of the high pressurized hydrogen storage tank and frequency assessment (FA) data to the general hydrogen refueling stations systems in expressway service area. In the cases of jet with a leak diameter of 7.16 mm, regardless of expressway service area location, the societal risk was over 1E-04 that was acceptable for as Low As reasonably practicable (ALARP) region (workforce), but unacceptable for ALARP region (public). In the cases of gas explosion, all expressway service area satisfy ALARP region. In the case of the population density is over 0.0727, QRA for constructing the hydrogen refueling stations, must be conducted.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1935-1945
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• 2023

The radiological safety of workers in a newly developed microwave-based spent resin treatment facility was assessed based on work location and operational scenarios. The results show that the remote-operation room worker was exposed to maximum annual dose of 3.19E+00 mSv, which is 15.9% of the dose limit, thereby confirming radiological safety. Inside the pathway, annual doses in the range of 7.87E-02-2.07E-01 mSv were measured initially at the mock-up tank and later at the point between the spent resin separation and treatment parts. The dose of emergency maintenance workers was below the dose limit (4.08E-03-4.99E+00 mSv); however, before treatment (separation and microwave), the dose of maintenance and repair workers exceeded the dose limit. The doses of the effluent removal workers at the zeolite and activated carbon storage tank and spent resin storage tank were the lowest at 2.79E-01-2.87E-01 mSv and 9.27E-01 mSv in "1 h" and "4-5 h of operation", respectively. The immediately lower and upper layers of the facility room exhibited the highest annual doses of 1.84E+00 and 3.22E+00 mSv, respectively. Through this study, a scenario that can minimize the dose considering the movement of spent resin through the facility can be developed.

• International Journal of High-Rise Buildings
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• v.9 no.2
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• pp.197-212
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• 2020

In this study, POE(Post Occupancy Evaluation) evaluation indexes were selected into six categories through the consideration of theories and prior research. Therefore, qualitative supply can be achieved through POE according to the aspect of residential environment after the quantitative supply of mixed-use apartment complex by the population concentration in Seoul due to industrialization and urbanization. As the evaluation elements, detailed survey contents were selected for livability, convenience, comfort, safety, economy, and sociality. Based on the survey contents, six elements were evaluated and analyzed using Data coding and Likert scale after surveying 12 complexes (Urban areas and non-urban areas) in Seoul. As a result of the study, six categories selected as the POE showed that importance of quality of life and safety was developed in high recognition according to high satisfaction with convenience and safety. Sociality showed the lowest satisfaction in the following order : livability, comfort, economy and sociality. Residents' sense of community, interaction with neighborhood, etc., showed low satisfaction, and it seems that it is necessary to improve and supplement the system for the development of mixed-use apartment complex in the future. The detailed characteristics of livability showed high satisfaction of the living room, the front door and the main room which are main uses of housing, and low satisfaction in storage size. The analysis of convenience is that convenient public transportation was the highest, and educational environment and additional facilities were the lowest, showing the advantages and disadvantages of location characteristics. As a result of the analysis of comfort, satisfaction with the landscape area was low and it seems that green space is needed for the development of mixed-use apartment complex in the future. Lastly, regarding the safety, the satisfaction of the access control, the location of security office, etc. were high, however separation of circulation was low. Therefore, it is necessary to clearly separate the circulation between the residence and other facilities in the mixed-use apartment complex.

• The Journal of Bigdata
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• v.2 no.1
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• pp.49-58
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• 2017

The inventory location is the mos important factor which decide the efficiency of picking orders. According to the inventory location, it is possible to optimize the route for picking order, and then it makes us to expect the cost reduction and efficiency improvement. However, it is practical situation to make decisions where to keep the products based on manager's intuition and experience, not based on the systematical or analytical approach. In this research, with the practical order data of cropper product and layout for the storage yard, the association rules have found, and then the new methodology has been devised to make the decision where to keep the inventory. By utilizing the practical order data for a year, it has been proved that the proposed approach can reduce the total distance of the all routes for picking order and solve the problem of delayed delivery.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.462-473
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• 2010

The RFID system has the security problem of location tracking and user privacy. In order to solve this problem, the cryptographic access method using hash function is difficult to in real applications. Because there is a limit of computing and storage capacity of Tag, but the safety is proved. The lightweight authentication methods like HB and LMAP guarantee the high efficiency, but the safety is not enough to use. In this paper, we use the AES for RFID Authentication, and solve the problem of using fixed key with key change step by step. The symmetric keys of the tag and server are changed by the random number generated by tag, reader and server successively. This could prevent the key exposure. As a result, the output of the tag and reader always changes. These key changes could make it possible to prevent eavesdropping, replay attack, location tracking and spoofing.

• Journal of Information Processing Systems
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• v.10 no.1
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• pp.103-118
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• 2014

Over the last couple of years, traditional VANET (Vehicular Ad Hoc NETwork) evolved into VANET-based clouds. From the VANET standpoint, applications became richer by virtue of the boom in automotive telematics and infotainment technologies. Nevertheless, the research community and industries are concerned about the under-utilization of rich computation, communication, and storage resources in middle and high-end vehicles. This phenomenon became the driving force for the birth of VANET-based clouds. In this paper, we envision a novel application layer of VANET-based clouds based on the cooperation of the moving cars on the road, called CaaS (Cooperation as a Service). CaaS is divided into TIaaS (Traffic Information as a Service), WaaS (Warning as a Service), and IfaaS (Infotainment as a Service). Note, however, that this work focuses only on TIaaS and WaaS. TIaaS provides vehicular nodes, more precisely subscribers, with the fine-grained traffic information constructed by CDM (Cloud Decision Module) as a result of the cooperation of the vehicles on the roads in the form of mobility vectors. On the other hand, WaaS provides subscribers with potential warning messages in case of hazard situations on the road. Communication between the cloud infrastructure and the vehicles is done through GTs (Gateway Terminals), whereas GTs are physically realized through RSUs (Road-Side Units) and vehicles with 4G Internet access. These GTs forward the coarse-grained cooperation from vehicles to cloud and fine-grained traffic information and warnings from cloud to vehicles (subscribers) in a secure, privacy-aware fashion. In our proposed scheme, privacy is conditionally preserved wherein the location and the identity of the cooperators are preserved by leveraging the modified location-based encryption and, in case of any dispute, the node is subject to revocation. To the best of our knowledge, our proposed scheme is the first effort to offshore the extended traffic view construction function and warning messages dissemination function to the cloud.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2586-2592
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• 2014

Lost fishing gears become a major cause of marine pollution, and many policy and technical efforts have been conducted for that. For efficient retrieving lost fishing gears in underwater, It is important to know the current position. Using GPS in the sub-sea environment is impossible and localization requires the use of special systems, and mobility due to water currents for underwater localization also has to be considered. In this paper, described with respect to the system for a self-generated location informations without using an external signal, such as a GPS and Sonar and storing them. Using the characteristics of the geomagnetic and INS principle, proposed informations and a way for estimating self position during movement. Embedded based system suggested and implemented in this study is tested for validating it's functionality.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.219-226
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• 2020

The container terminal operators established a re-marshalling plan to reduce the loading operation time and the release operation time. Re-marshalling is to rearrange the containers in the container yard to the advantageous position to shorten the working time using the spare time of the automated yard crane. This study assumed the automated container terminal with a perpendicular layout and deals with the inter-bay re-marshalling planning problem in a yard block. The inter-bay re-marshalling plan determines the container to be moved, the location to be relocated, and the sequence of relocation operations. This study presents a mixed integer programming model that simultaneously determines the storage location and the operation sequence while satisfying the spatial availability during the re-marshalling. Numerical experiments are conducted to understand re-marshalling operation using a beam search method.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.211-215
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• 2022

Air distribution occupies an important position in the smart unit load container design process for agricultural products. Inner air may be uncomfortable because of its temperature, speed, direction, and volume flow rate. It doesn't matter how efficient the ventilation equipment is if the air is not distributed well. The main aim of this study was to design the inlet and outlet fan locations of smart unit load container for agricultural products. A numerical study was performed on the effects of the location of inlet air and outlet air in relation to the container cooling sources on air distribution and thermal comfort. A concept of combining inner container cooling sources with the exhaust outlet was employed in this investigation. Also, in this research, the developed CFD (Computational Fluid Dynamics) models were thoroughly validated. This system was adopted for use in container spaces, where the exhaust outlet was located. In this study, the location of the inlet was derived through CFD for a container with a size of 1,100×1,100×1,700 mm, and it was derived that the inlet was located at the center of the lower part of the container for efficient air flow. It was efficient to position the outlet through the air inlet in the center of the lower part of the container at the top of the same side.