• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.4
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• pp.759-766
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• 2015

This paper proposes a location-based key management scheme in wireless sensor networks, and among the existing location-based key management techniques, we focused on the LDK (Location Dependent Key management). In order to improve the problems occurred by communication interference, we introduced the key revision process and the method of key establishment using grid information. According to the simulation of this scheme, it increased connectivity while decreased compromise ratio than those of the previous LDK, futhermore, we confirmed that a hexagon distribution of AN reduces the network cost.

• Journal of the Korean Society of Food Culture
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• v.8 no.3
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• pp.217-230
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• 1993

This study was conducted to evaluate the industry foodservice management practices in Pusan Kyeung Nam provinces and to suggest the guideline for the effective foodservice management. Questionnaire survey method were used in this study. Questionnaire were administered to 307 dietitians in Pusan Kyeung Nam. Data were analyzed for frequency, percentage, and ${\chi}^2-test$ using SPSS-X Package. The results are as follows: 61.7% of industry foodservice establishment serviced foods over three times a day and 18.0% of them were less 500 won in the cost of food. 64.5% of the dietitian had less 3 years experiences, and they are not fully performed the effective management in nutrition education, job design and utilization of standardized recipes. Equipped facilities in surveyed foodservice operations were assessed as the insufficient condition, especially, efficient facilities such as a cutting machine were scarcely make up.

• Journal of the Korean Society of Safety
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• v.25 no.5
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• pp.27-32
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• 2010

This study is to investigate and compare domestic hazardous toys with harmful substances with foreign toys so that we can find out management criteria for in cognitive infants. Actually, commercially used toys have been collected and tested to find out more effective management standard. it is tried to produce evaluation criteria of environmentally harmful substance but variety of product is needed for overcoming actual barrier due to lot of difficulty huge cost, time, objectiveness. Therefore, This study does not cover all the above. Establishment of evaluation criteria for product harmfulness made by Government or Local government should be continued to improve. Foreign reference material for toy product in Europe, USA, Japan have been investigated and domestic product have been collected and tested for containing heavy metals, formaldehyde, phthalate in the study. All the test have been made in accordance with KSM ISO 2124 to measure heavy metal transfer into body. Toy product used for the study have been purchased in the real market and some of them contains harmful elements with over standard. Post management system such as RAPEX to control periodically should be established for plastic toy with low quality product.

• Journal of Information Technology Services
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• v.5 no.2
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• pp.125-136
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• 2006

In general, the distribution structure of marine products is very vulnerable to the uncertainties in the process from the production to the sale, and a lot of difficulty is thus inevitable in the supply control. Such a distribution structure is a very critical issue in securing the suability of marine products through systematic quality and hygiene control of marine products, and it is thus time to discuss the method to innovate and restructuring the distribution structure of marine products. From this point of view, this study approached the flow from production to consumption in view of SCM(supply chain management) beyond the partial discussion conducted so far for the distribution structure in the field of marine products. Further, this study suggested the establishment of electronic commerce systems with a traceability system built in RFID for marine products as an alternative of redesigning distribution infrastructure in the ubiquitous environment. From the results, we assured that such an electronic commerce system would be a new measure to improve the structure currently causing inefficiency and excessive distribution cost for the distribution structure of marine products.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.2
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• pp.21-26
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• 2000

Flow forming is a chipless metal forming method for axi-symmetric parts, which is more economical. efficient and versatile method of producing parts than the other sheet metal forming process such as stamping or deep drawing. In this study, flow forming process with 1-Roller is applied to produce auto-transmission parts of automobiles which have been produced by Press drawing process so far. It can be known that flow forming process is applicable to the flexible manufacturing system due to the low cost for the establishment and it can be combined with press forming process to promote productivity and to improve the accuracy of products.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.662-668
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• 2016

No-tillage dry-seeding of rice can offer potential benefits by reducing time and labor cost compared with conventional tillage practices. This study was conducted to investigate the effects of no-tillage dry-seeding on rice growth and soil hardness in comparison with other rice cultivation methods, machine transplanting and wet-hill-seeding on puddled paddy. The seedling stand fell within optimum range for both no-till dry-seeding and wet-hill-seeding on puddled paddy. Plant height, number of tillers and SPAD values in no-tillage dry-seeding cultivation were higher than those observed in other methods. There were no significant differences in grain yield of rice among three cultivation methods. The quality characteristics of milled rice grown in no-tillage dry-seeding were similar to those grown in other cultivation methods. Soil hardness in top 10 cm depth was significantly higher in no-tillage dry-seeding than other cultivation methods, while soil hardness below 10 cm depth was highest in machine transplanting cultivation. Results indicate that no-tillage dry-seeding practice is comparable to conventional tillage system in terms of seedling establishment, growth, yield and grain quality.

• Convergence Security Journal
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• v.15 no.3_2
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• pp.71-76
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• 2015

Global companies are building global production network for the demand of the global market. However, the establishment and operation of overseas plants make the unexpected case like theft, low will to produce and salary issue of local workers. Thus in this paper, we propose the raw materials loss prevention model based on IP Camera and RFID Box for raw materials management of overseas plants. This model can prevent the theft or loss of raw materials write inventory up in real-time. This model can be allows us to realize the cost-effective production management because it enables remote inventory management. And this model can prevent brand image danage and profit loss due to reject product.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.6
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• pp.1382-1390
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• 2010

A multicast session protocol in wireless networks reduces the session delay of multicast delivery caused by moving of mobile host. A hand-off scheme, called MSDR (multicast session delay reduction), in mobile networks is proposed. MSDR protocol that minimizes the delay of a session re-establishment uses the basic unicast routing function of the IETF mobile IP and the DFA (designated foreign agent) to provide multicast services for mobile hosts. Proposed MSDR protocol allows the mobile hosts to continuously receive packets when they move across the basic sets during hand-off. Discrete-event simulation carried out for performance evaluation of MSDR protocol, and simulation results indicated that our scheme can offer a better performance of multicast session delay reduction in terms of signalling cost than that of IETF.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.799-806
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• 2004

Recently, as the forerunner in establishing the Northeast Asia's logistics base, a lot of marine engineering works such as new ports and container terminals, extension of old ports, new bridges, land reclamation etc. have been progressed. Parallel to it, there is also an increasing demand for improving the safety of construction. In this situation, high resolution seismic reflection profiling can be well used, attempting to classify rocks and sediments under water, if possible, to delineate the distribution of grain sizes in sediments not only for calculating the cost of removing sediments from harbour's channels, but also for estimating the bearing capacities for bridge or port construction. However, the results from the corresponding reflection survey that has been in operation in our country can not be effectively used for engineering purposes mostly due to the insufficient resolution. Thus. in this paper, two innovative strategies are introduced to enhance resolution. The one deals with a newly designed exploration barge that will help reduce several kinds of noises encountered electrically or operationally. The other is associated with an establishment of optimum measuring system comprising e.g. a specially devised hydrophone with a combination of 7 piezoelectric elements. Field experiments performed at Busan harbour are illustrated. The quality of acquired data was thereby fundamentally improved in comparison with that obtained at the same time in a conventional way.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1401-1407
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• 2002

This paper represents an investigation of the vehicle-to-vehicle distance control system using Hardware-in-the-Loop Simulation(HiLS). Control logic is primarily developed and tested with a specially equipped test vehicle. Establishment of an efficient and low cost development tool is a very important issue, and test vehicle approach is costly and time consuming. HiLS method is useful in the investigation of driver assistance and active safety systems. The HiLS system consists of a stepper motor for throttle control, a hydraulic brake system with an electronic vacuum booster, an electronic controller unit, a data logging computer which are used to save vehicle states and signals of actuator through a CAN and a simulation computer using mathematical vehicle model. Adaptation of a CAN instead of RS-232 Serial Interface for communication is a trend in the automotive industry. Since this environment is the same as a test vehicle, a control logic verified in laboratory can be easily transferred to a test vehicle.