• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2167-2171
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• 2016

The purpose of the cultivated crops have been changes in the aim of improving quality production. In recent years, as people's attention on health, the demand for healthy crops such as mushrooms gradually increased. In the process of mushroom factory production, regulation of environmental factors directly affects the yield and quality of mushroom. In related to the methods of mushroom cultivation, the recent technologies apply the new technology such as sensors and IT convergence services. And then cultivating mushroom is managed effectively. Farmers use plastic greenhouse cultivation mode more and more in order to reduce the impact of outdoor environment on crop cultivation, which requires farmers to adjust the greenhouse temperature at any time. But the majority of farmers still use a thermometer to measure temperature. This paper constructs an environment that can automatically adjust the temperature, so as to measuring temperature in real time, improving the efficiency of the farm work, and reducing unnecessary labor.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.415-426
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• 2006

The essential characteristic of ubiquitous is context-awareness, and that means ubiquitous computing can automatically process the data that change according to space and time, without users' intervention. However, in circumstance of context awareness, since location information is able to be collected without users' clear approval, users cannot control their location information completely. These problems can cause privacy issue when users access their location information. Therefore, it is important to construct the location information system, which decides to release the information considering privacy under the condition such as location, users' situation, and people who demand information. Therefore, in order to intercept an outflow information and provide securely location-based information, this paper suggests a new system based CS-RBAC with the existing LBS, which responds sensitively as customer's situation. Moreover, it accommodates a merit of PCP reflecting user's preference constructively. Also, through privacy weight, it makes information not only decide to providing information, but endow 'grade'. By this method, users' data can be protected safely with foundation of 'Role' in context-aware circumstance.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.34-39
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• 2015

Recently, most of the energy consumed in vehicle is derived from fossil fuels. For this reason, the demand for clean, renewable and affordable alternative energy is forcing the automotive industry to look beyond the conventional fossil fuels. Natural gas represents today a promising alternative to conventional fuels for vehicles propulsion, because it is characterized by a relatively low cost, better geopolitical distribution than oil, lower environmental impact, higher octane number and a higher self ignition temperature. Above all, CNG is an environmentally clean alternative to the existing spark ignition engines with the advantages of minimum change. In this study was installed bi-fuel system that a conventional 2 liters gasoline engine was modified to run on natural gas by a gas injection system. Experiments were mainly carried on the optimization of an ECU control strategy affecting the emission characteristics of CNG/Gasoline bi-fule vehicle. The test results shown that CO2 emission in bi-fuel mode was reduced 16% compared to gasoline fuel in the NEDC mode. Also the amount of CO and HC emissions in bi-fuel and gasoline modes were found to equality. But Compared to gasoline, the bi-fuel mode resulted in higher NOx emissions.

• Journal of the Korean Institute of Navigation
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• v.20 no.2
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• pp.1-13
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• 1996

Most of the ShipHandling Simulators of full-mission-bridge system need vast area to install and even PC-based maneuvering simulators are often equipped with Steering Wheel or Engine Telegraphe etc. of data input interface, which necessarily makes the user face with excessive financial burden. These have been one of the obstacles for the officers, captains, pilots and students in access to maneuvering simulation whenever they want to try it in advance prior to actual ship maneuvering. Subsequently, all the officers and captains come to have little chances to train themselves until they arualified as a pilot after a long period of time of realship maneuvering practice on board, which means they have to control they have to control their own ship at sea without clear understanding on her maneuverability when they are forced to do it on the way. And these lack of capability for maneuvering have used so often to result in marine casualties of collision with other ships or pier facilities while maneuvering in harbor. To prevent those accidents by means of enhancing their maneuvering ability, PC-based DeskTop Simulator that allows anyong to access readily at anytime is needed and in conformation to such demand this simulator has been developed. The Software this simulator written in Turbo Pascal Ver. 5.0 has adopted MMG mathmatical model theoretically in part and also it was designed to make it possible that all numeric data inputs and outputs with graphic presentation for maneuvering operation be carried out just only with keyboard and monitor console. With the Simulation software, all the officers, captains, pilots and even students who has a proper computer at hand are expected to be able to make an attempt to simulate the maneuvering of their ownship or any other types of them at any port in which they want to do it.

• Journal of Welding and Joining
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• v.30 no.4
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• pp.31-37
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• 2012

In recent years, a demand for precision-welding is increasing in wide industrial fields for getting a high quality welded structures. Although laser welding is commonly used for precision-welding, gas tungsten arc (GTA) welding is also attempted as a precision-welding due to the cost benefit. However, welding heat causes an uneven temperature distribution leading to welding deformation. Since it causes geometric errors and degrades product quality, welding distortion recently rises as an important issue in the field of automobile parts. To control welding deformation, it is needed to design in shapes that can maximize stiffness against deformation during welding; control the welding sequence; minimize heat input; and weld allowing reverse deformation; etc. Thus it is necessary to find the one, among such approaches, that can minimize the deformation range by mathematical analysis and understand how effective it would be when it is actually used in industrial fields. This study performs analyses by numerical calculations and experiments for the De-Tent Lever, one of transmission part that requires precision the most among automobile parts, as the subject of experiment. Decrease in welding deformation is required for this part, since there is currently a trouble in guaranteeing precision due to angular deformation by welding between boss and plate. Finally the ways to minimize welding deformation has been suggested in this study through analyses on it.

• Journal of Welding and Joining
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• v.25 no.6
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• pp.71-77
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• 2007

Until now, many researches on laser-arc hybrid welding processes have been conducted mainly for high power CW laser and high direct current arc to weld the thick steel plates for shipbuilding. Recently, however the usage of thin steel plates, which tend to be deformed easily by thermal energy, is been increasing because of demand of light structure such as car body in the automobile industry. Accordingly, heat sources having relatively low heat input such as pulsed laser, dip-transfer DC GMA and pulsed GMA seem to be applied more increasingly and the study about those heat sources is needed more intensively. Any heat source mentioned above can not stand alone without weld defects at a relatively high welding speed for increasing the welding productivity. This is main reason to apply the hybrid welding process which uses pulsed laser and low-heat-input GMA heat sources simultaneously to weld the thin steel plate. In this study, parameters of pulsed laser and dip-transfer DC GMA welding are studied firstly through preliminary experiments, and then analyzed in the viewpoint of their physical phenomena. Before conducting the hybrid welding, a pulse control technique is developed based on the parallel port communication and Visual C++ 6.0. Owing to development of this technique, interactions of laser and arc pulses can be controlled consistently. Using the pulse control technique, the hybrid welding is conducted and then its interactive welding phenomenon is analyzed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.11
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• pp.833-839
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• 2002

As the demand for slim laptops requires low-height optical disc drives, vibration problems of optical disc drives are of great concern. Additionally, with the decrease of a track width and a depth of focus in high density drives, studies on vibration resonance between mechanical parts become more important. From the vibration point of view, the performance of optical disc drives is closely related with the relative displacement between a disc and an objective lens which is controlled by servo mechanism. In other words, to read and write data properly, the relative displacement between an optical disc and an objective lens should be within a certain limit. The relative displacement is dependent on not only an anti-vibration mechanism design but also servo control capability. Good servo controls can make compensation for poor mechanisms, and vice versa. In a usual development process, robustness of the anti-vibration mechanism is always verified with the servo control of an objective lens. Engineers partially modify servo gain margin in case of a data reading error. This modification cannot correct the data reading error occasionally and the mechanism should be redesigned more robustly. Therefore it is necessary to verify a mechanism with respect to the possible servo gain plot. In this study we propose the experimental verification method for anti-vibration mechanism with respect to the existing servo gain plot. Thismethod verifies axial vibration characteristics of optical disc drives on the basis of transmissibility. Using this method, we verified our mechanism and modified the mechanism for better anti-vibration characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3470-3476
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• 2012

In this study, for cadastral surveying specified in current relevant legislation, regulations of allowable error tolerance and applicable equipments, accuracy in the relevant regulations and applicable regulations were comprehensively studied. Based on them, the objective was to develop performance standard for cadastral surveying equipments satisfying allowable error tolerance of cadastral surveying specified in the special law for cadastral re-survey. The study results are as follows. By comparing current legislation for performance and allowable error tolerance of applicable equipments with provisions of the special law for cadastral re-survey, analyzed were where performance of equipments needs to be improved on cadastral re-survey project. Based on them, as primary control point surveying and detail surveying were separated, performance standard of equipments were presented. Results of this study may be utilized as basic materials for supply and demand program of surveying equipments on establishment of the basic plan for cadastral re-survey project.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.23-31
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• 2019

With the advent of the era of mass tourism in China and people's yearning for a better life, the demand for family tourism is increasing. This paper adds the filial piety concept variable to the original model based on the theory of planned behavior (TPB). It tests the influence mechanism of attitude, subjective norm, perceived behavior control and filial piety on the intention of family tourism behavior. The results show that； Attitude and subjective norms have significant influence on the intention of family tourism behavior; Perceptual behavior control has no significant influence on the intention of family tourism behavior; Mutual filial piety has a significant impact on family tourism behavior and authoritative filial piety has no significant effect on family tourism decision-making behavior. This conclusion expands the application boundary of the theory of planned behavior in the study of family tourism behavior intentions, and provides application reference for tourists and tourism enterprises.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.780-783
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• 2009

The application of MOST150 technology has been required to satisfy the demand for the automotive infotainment system and the higher bandwidth requirements caused by the increase of the multimedia processing capacity. The Ethernet technology applied gateway was implemented for an efficient transmission of multimedia, a vehicle diagnosis, an external communication, a data processing between the MOST150 and the CAN communication method applied to many existing vehicles. The new algorithm and application were suggested in order to efficiently perform the data processing between other types of communication systems. The existing MOST150 frame is mainly composed of the Control Channel, the Legacy Packet Channel(async) and the Synchronous /Isochronous Channels and performs the data processing through these sequential channels. With the sense of this process, this study suggested the new algorithm that the Mapping method of the IETF's QoS Management was applied to the MOST150 technology for the efficient QoS.