• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.4
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• pp.441-451
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• 2019

When a store is launched, the umbilical plug should be separated from the launcher without any physical interference and fragments. In order to satisfy these conditions, an umbilical plug and an umbilical separating device were designed. The plug is separated from the receptacle of the store while moving along inclined planes by the store thrust and the spring force connected from the launcher to the plug. As a result of the prototype test, the hanger on the store collided with the plug. Several tests were conducted after some actions were taken to prevent the collision. However, not only the same phenomenon was repeated, but also fragmentation occurred. In this study, the non-colliding conditions were analyzed through rigid and flexible multi-body dynamics analysis.

• Journal of Agricultural Extension & Community Development
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• v.12 no.1
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• pp.109-118
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• 2005

This study was carried out to identify the major characteristics of plug seedling farm's management. Thirty glasshouse farms were surveyed out of 42 farms that adopted plug seedling production technology in Korea. The major objectives of this survey were to determine the technical capability of the glasshouse farmers, and to analyze the significant differences in terms of production performance and management capabilities. The major results of the survey were as follows : 1) The production quantity of plug seedlings of the superior group was 43% higher than the inferior group. 2) The plug seedling loss rate of the superior roup was lower by 4% than the inferior group. 3) The income of superior group was 4.2 million Won per $1,000m^2$, while the income of the inferior group was only 0.45 million Won. 4) The cause of low production of grafted plug seedlings was primarily due to the lack of technical knowledge and skills. 5) The results indicated that the technical knowledge level and production skills of grafting plug seedling should be improved.

• Journal of Biosystems Engineering
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• v.21 no.4
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• pp.429-435
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• 1996

A wind tunnel consisting of two air flow conditioners with polycarbonate pipes, a plant growth room, a suction fan and fan controller, and fluorescent lamps, was designed to investigate the interactions between the growth of plug seedlings under artificial light and their Physical environments. Light transmissivities in the plant growth room based on the photosynthetic photon flux density and photosynthetically active radiation was appeared to be 96.3% and 96.8%, respectively. Measurement showed a uniformity in the vertical profiles of air current speed at the middle and rear regions of plug trays in wind tunnel. This result indicated that the development of a wind tunnel based on the design criteria of the American Society of Mechanical Engineers was adequate. Air current speed inside the plug stand was significantly decreased due to the resistance by the leaves of plug seedlings and boundary layer developed over and below the plug stand. Driving force to facilitate the diffusion of gas inside the plug stand might be regarded as extremely low. Aerodynamic characteristics above the plug stand under artificial light were investigated. As the air current speed increased, zero plane displacement decreased but roughness length and frictional velocity increased. Zero plane displacement linearly increased with the average height of plug seedlings. The wind tunnel developed in this study would be useful to investigate the effects of air current speed on the microclimate over and inside the plug stand and to collect basic data for a large-scale plug production under artificial light in a semi-closed ecosystem.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.4
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• pp.8-13
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• 2005

Interoperability has been the problem of CAD/CAM systems. Starting from 1980's, national and international organizations have addressed the issue through development and release of standards for the exchange of geometric and nongeometric design data. To CAD/CAM vendors, the task of interpreting and implementing these standards falls into their products. This task is a balancing action between users' needs, available development resources, and the technical specifications of standards. This paper explores an area of CAD/CAM systems development, particularly the implementation of the effective exchange files translators'. A new approach is introduced, which proposes to enclose all the translation operations concerning each exchange format to a separate DLL, thus making a 'plug-in.' Then, this plug-in could be used together with the CAD/CAM system or with specialized translation software. This approach allows to create new translators rapidly and to gain the reliable, high-efficiency, and reusable program code. The second part of the paper concerns the possible problems of translators' development. These difficulties often come from the exchange standards' misunderstanding or ambiguity in standards. All examples come from the authors' practice experiences of dealing with CAD/CAM systems.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.381-390
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• 2018

This study was conducted to examine the growth characteristics of seedlings of several major fruit vegetables and compare them between plants grown with the conventional plug seedling system (Plug) and those grown with the cylindrical paper pot system (CPP). There were no significant differences in shoot growth characteristics, such as plant height, leaf area, dry weight, and fresh weight, between tomato, cucumber, and watermelon plants grown with the CPP and Plug systems. The total root lengths of tomato and cucumber plants grown with Plug were longer than those grown with CPP at the beginning of seedling growth, and the total root lengths of watermelon grown with Plug were longer than those grown with CPP throughout the whole seedling period. The length of root that separated five steps according to the diameter of the root of tomato did not differ between CPP and Plug, but those of cucumber and watermelon were 20-251% longer with Plug than with CPP for all kinds of roots. The fresh weight of Plug-grown tomato roots was about 30% heavier than that of CPP-grown tomato during the seedling period, but the difference decreased as growth progressed. Finally, there was no difference between plants before and after transplanting. The fresh weights of the Plug-grown plants were about 20-30% heavier than those of CPP-grown ones in terms of the whole seedling. After transplanting to the Wagner pot, the shoot growth of Plug-grown watermelon plants in terms of dry weight was low until 7 days had passed. However, this tendency was reversed from 8 days after transplantation onward. In conclusion, there were no significance differences in the growth of shoots between plants grown with the CPP and Plug systems. However, root development was better with Plug than with CPP.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.3
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• pp.46-57
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• 1995

The aim of the present study is to provide fundamental informations for the development of magneticfluid actuator. To achieve the aim, oscillation characteristics of the magneticfluid plug are investigated by experiment for the various length and position of the magneticfluid plug and the frequency of magnetic field. The oscillation characteristics are obtained. Amplitude, natural frequency, phase shift and damping ratio, are compared with theoretical values. From the study, the following conclusive remarks can be made. The experimental equation for the magnetic field is obtained. The critical magneticfluid length exists and its value is about 70mm. The range of the damping ratio and fluid loss coefficient obtained by experiment are 0.1~0.2 and 30~100, respectively. Comparison between experimental and theoretical results of oscillation characteristics shows good agreement in the high frequency range. Meanwhile, in the low frequency range, there appears little discrepancies(5% in the frequency and amplitude and 10% in phase difference and damping ratio) with each other.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.1
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• pp.70-77
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• 2007

Simulation Based Acquisition(SBA) gains interest from the defense acquisition community. To accomplish SBA efficiently, M&S should be collaborately used in. This paper proposes PBA(PlugIn-Based Architecture) that is a common software development infrastructure and provides reuse mechanism with plugin components. PlugIns are reuse entity possible to plug-in-play statically and dynamically. This architecture supports stand alone simulation and HLA-compliant distributed simulation also.

• Journal of the Korean Society for Railway
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• v.5 no.2
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• pp.112-117
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• 2002

Reduction of noise level in the cabin of urban transit unit is an important issue to enhance the comfortability of passengers. It is made clear that a cause of increased noise level in cabin is the imperfect airtightness of entrance doors. In this study, the sliding-plug door system is developed to reduce the noise level of cabins by securing the airtightness of entrance door. The sliding-plug door system is composed of air-driven engine, swing arms, guide rails, guide rollers and locking devices. It is economical owing to using the previous door engine system. It is also adequate for the platform system of our subway station. It was tested to prove the reliability of system and was applied to standard urban transit unit. The effectiveness of noise reduction in cabin resulting form the sliding-plug door system was confirmed by test results.

• Journal of Multimedia Information System
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• v.9 no.3
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• pp.209-218
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• 2022

Industrial IoT applications, including smart factories, require two problem-solving to build data monitoring systems required by services from distributed IoT sensors (smart sensors). One is to overcome proprietary protocols, data formats, and hardware differences and to uniquely identify and connect IoT sensors, and the other is to overcome the problem of changing the server-side data storage structure and sensor data transmission format according to the addition or change of service or IoT sensors. The IEEE 1451.4 standard-based or IPMI specification-based smart sensor technology supports the development of plug-and-play sensors that solve the first problem. However, there is a lack of research that requires a second problem-solving, which requires support for the plug-in of IoT sensors into remote services. To propose a solution for the integration of these two problem-solving, we present a IoT sensor platform, a service system architecture, and a service plugin protocol for the MQTT-based IIoT application environment.

• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.81-94
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• 2009

Research of reusability and variability design for embedded system development is insufficient. An embedded system should be designed to support new devices. If extensibility of embedded system is not considered, it is difficult to reconstruct. Currently, the development productivity and reusability of embedded system are very poor, and this will be cased about problems of increasing maintenance and development cost, and decreasing system quality such as software crisis. In this paper, we present framework of embedded system that address those problems of embedded system. We suggest a plug-in technique, based on reusability framework, which can support various devices dynamically. Also, we propose a dynamic Meta model which is base on plug-in technique.