• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.331-341
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• 2014

Internet of Thing(IoT), which is recently talked about with the development of information and communication technology, provides big data to all nodes such as companies and homes, means of transportation etc. by connecting all things with all people through the integrated global network and connecting all actual aspects of economic and social life with Internet of Thing through sensor and software. Defining Internet of Thing, it plays the role of a connector of providing various information required for the decision-making of companies in the cloud computing environment for the Insight usage by collecting and storing Raw Data of the production site through the sensor network and extracting big data in which data is accumulated and Insight through this. In addition, as the industry showing the largest linkage with other root industries among root industries, the mold industry is the core technology for controlling the quality and performance of the final product and realizing the commercialization of new industry such as new growth power industry etc. Recently, awareness on the mold industry is changing from the structure of being labor-intensive, relying on the experience of production workers and repeating modification without the concept of cost to technology-intensive, digitization, high intellectualization due to technology combination according to IT convergence. This study, therefore, is to provide a golden opportunity to increase the direct and indirect expected effects in poor management activities of small businesses by actually implementing and managing the entire process of mold life cycle to information system from mold planning to mass production and preservation by building SME(small and medium-sized enterprises)-type mold life cycle management information system in the cloud computing environment and applying it to the production site.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.4
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• pp.3-14
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• 2001

A Web server makes use of the HTTP(Hyper Text Transfer Protocol) to communicate with a client. The HTTP is a stateless protocol; the server does not maintain any state information for ongoing interactions with the client. Therefore, the HTTP inevitably requires additional overhead as repeating data key-in to user for continuing communications. This overhead in Web environment can be resolved by the cookie technologies. However, the cookie is usually unsecured due to the clear-text to transfer on the network and to store in the file. That is, information in the cookie is easy to exposure, copy, and even change. In this paper, we propose a secure cookie mechanism appropriate to Web environment, and then present a design and implement of secure Web system based on the scheme. The Web system can be used to any web environment. It also provides some security services, such as confidentiality, authentication, integrity.

• Journal of Creative Information Culture
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• v.7 no.3
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• pp.167-176
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• 2021

In this paper, from the pervious studies investigating the current status of distance learning due to COVID-19, the needs of teachers for effective distance learning were analyzed. As a result, it was found that support related to distance learning contents was necessary. Specifically, it is necessary to establish a platform specialized for content production for distance learning, expand teacher training related to content production and operation, and improve the copyright system related to content production. In addition, since distance classes differ from those of back-to-school classes in system and characteristics, it is necessary to supplement the institutional aspects for distance classes. It is judged that it is necessary to support the evaluation method suitable for distance learning, the authority to operate the curriculum, and the learning management system. In addition, it was analyzed that it is necessary to expand the infrastructure for distance learning, and a structure and platform for self-directed improvement programs and self-directed distance learning are needed to prevent the learning gap problem from repeating due to distance learning.

• Biomedical Science Letters
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• v.29 no.4
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• pp.363-370
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• 2023

Human respiratory viral infections such as COVID-19 are highly contagious, so continuous management of airborne viruses is essential. In particular, indoor air monitoring is necessary because the risk of infection increases in poorly ventilated indoors. However, the current method of detecting airborne viruses requires a lot of time from sample collection to confirmation of results. In this study, we proposed a system that can monitor airborne viruses in real time to solve the deficiency of the present method. Air samples were collected in liquid form through a bio sampler, in which case the virus is present in low concentrations. To detect viruses from low-concentration samples, viral RNA was concentrated and extracted using silica-magnetic beads. RNA binds to silica under certain conditions, and by repeating this binding reaction, bulk samples collected from the air can be concentrated. After concentration and extraction, viral RNA is specifically detected through real-time qPCR (quantitative polymerase chain reaction). In addition, based on liquid handling technology, we have developed an automatic machine that automatically performs the entire testing process and can be easily used even by non-experts. To evaluate the system, we performed air sample collection and automated testing using bacteriophage MS2 as a model virus. As a result, the air-collected samples concentrated by 45 times then initial volume, and the detection sensitivity of PCR also confirmed a corresponding improvement.

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.193-201
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• 2009

Structural design of most nonprismatic Pre-Engineered Building Systems (PEBS) is performed using optimizing software developed in foreign countries. In this study, a structural optimizing software for the design of 3-D structures of nonprismatic PEBS is developed according to the allowable stress design method of AISC2005 and KBC. Optimizing structural design with nonprismatic members is carried out by repeating the process of structural analysis and member design to minimize the weight of a structure. According to the optimizing design results of 2-D and 3-D structures with nonprismatic members, there are considerable steel savings in designing structures with nonprismatic H-shaped built-up sections rather than with H-shaped rolled sections. When H-shaped built-up sections were used, the weight of the structural steel was reduced when AISC2005 specification rather than AISC1898 was used in the design. It is therefore concluded that utilizing the new AISC2005 specification is safer in preventingweb buckling because the height of a member is designed to be small despite some differences depending on the structural type.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.1
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• pp.71-75
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• 2008

Many sensor operating systems have memory limitation constraint; therefore, stack memory areas of threads resides in a single memory space. Because most target platforms do not have hardware MMY (Memory Management Unit), it is difficult to protect each stack area. The method to solve this problem is to exchange original stack handling instructions in binary code for wrapper routines to protect stack area. In this exchanging phase, instruction corruption problem occurs due to difference of each instruction length between stack handling instructions and branch instructions. In this paper, we propose the algorithm to call a target routine without instruction corruption problem. This algorithm can reach a target routine by repeating branch instructions to have a short range. Our solution makes it easy to apply security patch and maintain upgrade of software of sensor node.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1163-1168
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• 2011

Most transformers use insulating and cooling fluids derived from petroleum crude oil, but mineral oil has some possibility of environmental pollution and fire with explosion. vegetable oil fluids extracted from seed has superior biodegradation and fire-resistant properties including an exceptionally high fire point enhancing fire safety. In this study, it is aimed at the practicality of substituting natural ester dielectric fluid for mineral oil in liquid insulation system of transformers. As a rise in coil winding temperature has a direct influence on transformer life time, it is important to evaluate the temperature rise of coil winding in vegetable oil in comparison with mineral oil. Four transformers for the test are designed with 10KVA, 13.2KV, one phase unit. The temperature are directly measured in insulating oil of these transformers with the two sorts of natural ester and mineral oil dielectric fluid respectively. Experiment for aging carry out two means. First means remained $120^{\circ}C$ that transformer of mineral oil were operated at 185% load. Second means is that insulating oils of two natural ester and mineral oil were aged by thermal cycles repeating from $30^{\circ}C$ to $120^{\circ}C$. For the heating, Transformers were operated at 185% load. For the cooling, cooling system was operated in the chamber. Samples were analyzed at 42, 63, 93, 143, 190, 240 300cycles. Analysis contents are dielectric strength, total acid value. Mineral oils compared results of first means with results of second means. And compared two sort natural esters respectively with mineral oil in second means.

• Journal of Institute of Convergence Technology
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• v.5 no.1
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• pp.13-17
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• 2015

In wafer level molding progress, the thermal releasing failure phenomenon is shown up as the important problem. This phenomenon can cause the problem including the warpage, crack of the molded wafer. The thermal releasing failure is due to the insufficiency of adhesion strength degradation of the molding tape. To solve this problem, we studied experimental method increasing the release property of the molding tape through the plasma surface treatment on the wafer substrate. In this research, the vacuum plasma treatment system is used for release property improvement of the molding tape and controls the operating condition of the hydrophilic($O_2$, 100kW, 10min) and hydrophobic($C_2F_6$, 200kW, 10min). In order to perform the peeling test for measuring the releasing force precisely, we remodel the micro scale material property evaluation system developed by Korea institute of industrial technology. In case of hydrophilic surface treatment on the wafer substrate, we can figure out the releasing property of molding tape increase. In order to grasp the effect that it reaches to the release property increase when repeating the hydrophilic treatment, we make an experiment with twice treatment and get the result to increase about 12%. We find out the hydrophilic surface treatment method using plasma can improve releasing property of molding tape in the wafer level molding process.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.6
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• pp.47-54
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• 2008

In this paper, interference analysis has been performed between RF receiver and transmitters on each soldier for Multiple Integrated Laser Engagement System(MILES) which are following ZigBee standard. In order to obtain minimum transmit power without interference, 1% Packet Error Rates(PER) from 14 transmitters attached on a soldier to a receiver are measured with the scenarios for simple transmitting and receiving network configuration and for repeating network configuration. Based on this transmit power, the available distance for interference free among soldiers is simulated using Spectrum Engineering Advanced Monte Carlo Analysis Tool(SEAMCAT). Later scenario gives the benefit of 10dB lower transmit power, smaller and lighter power source, and better activity of trainee.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.774-787
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• 2011

This paper deals with quantitative analysis about the characteristics of GNSS(Global Navigation Satellite System) signals contaminated with multipath signals and day-to-day repeatability of the navigation solution and SNR(Signal to Noise Ratio) caused by multipath signals using the collected data from GPS receiver installed on KSLV-I which was on standby on the launch pad at Naro Space Center. Since the GPS antennas, surrounding environments and GPS satellite orbits were very slightly changed with respect to the day, the repeating pattern of the solution and SNR caused by the multipath signals was verified from the collected data. Analytic result of the multipath effects and day-to-day repeatability of the navigation solution and SNR observed at the launch pad would be used for obtaining more stable performance of the GPS receiver when the satellite launch vehicles are on standby.