• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.6
• /
• pp.868-874
• /
• 2002

A high-impulse, low-power, digital microthruster has been developed using low-boiling-temperature liquid propellant with high-viscosity fluid plug. The viscous fiction force of the fluid plug increases the blast pressure and the low-boiling-temperature liquid propellant is intended to reduce input power consumption. The three-layer microthruster has been fabricated by surface micromachining as well as bulk micromachining in the size of 7$\times$13$\times$1.5㎣. A digital output impulse bit of 6.4$\times$10$^{-8}$ Nsec has been obtained from the fabricated microthruster using perfluoro normal hexane (FC72) propellant and oil plug, resulting in about ten times increase of the impulse bit using one hundredth electrical input energy compared to the conventional multiple-shot microthruster.

• Journal of Bio-Environment Control
• /
• v.27 no.1
• /
• pp.71-79
• /
• 2018

This study was conducted to compare the physicochemical properties of newly developed artificial medium and conventional plug medium and to investigate the proper irrigation interval to produce the high quality tomato seedlings. The five existing artificial media (organic medium coir, mixed medium Tosilee and Q plug, and inorganic medium LC and rockwool) and four newly developed artificial medium (mixed medium TP-S1 and inorganic medium PU 14-S1, PU-7B, and PU 15-S1) were used to grow tomato 'Yegwang' with irrigation interval of one-day (14 times), two-day (7 times), and three-day (5 times) for 14 days. The pH was the significantly highest in the PU 15-S1. All growing medium measured were in the range of pH 5.17-6.90. EC was the highest in the Q plug. The initial germination rate was the highest in the PU 15-S1. The final germination rate and mean daily germination were not significantly different in all growing medium except for the PU 14-S1. Growth of tomato seedlings at 15 days after sowing was the greatest in the Q plug. At 29 days after sowing, seedlings were also the greatest in the Q plug, followed by rockwool and PU-7B. Also, growth was better in the one-day interval treatment. As a result, we confirmed the applicability of the artificial medium to tomato plug seedlings in this experiment, and seedlings were the greatest in the Q plug. Therefor, it is considered that adding nutrients to the artificial medium of the newly developed medium PU-7B, and applying the irrigation one-day interval can produces high quality tomato seedlings similar to using Q plug.

• Journal of Bio-Environment Control
• /
• v.13 no.2
• /
• pp.81-89
• /
• 2004

This study was conducted in a commercial plug glasshouse in Sacheon to examine the possibility of producing tomato plug seedlings using various growing media containing cellular glass foam (CGF)and carbonized chestnut woodchips (CCW) as medium components. Plug seedlings of 'Seogun' tomato were grown in media containing 50% CCW＋50% peatmoss, 33% CGF＋67% peatmoss, and 50% peatmoss＋50% granular rockwool. A commercial plug medium (Tosilee) was used as the control. All seeds were sown in 200 cell plug trays on November 28, 2001. Seedling growth was measured at 31 days after sowing. Each treatment showed a similar growth result as compared to the control. Plant height, root grade, fresh weight, and air space and bulk density of the medium were significantly greater in the 33% CGF＋67% peatmoss treatment than those in the other media. However, growth was slightly suppressed in the 50% CCW＋50% peatmoss. pH and EC of the media were the highest in the control treatment, although no toxicity symptoms had been observed. The results suggest that perlite can be replaced with a new material such as CGF in the commercial scale production of plug seedlings of 'Seogun' tomato.

• Korean Journal of Materials Research
• /
• v.20 no.6
• /
• pp.338-343
• /
• 2010

As an alternative to the W plug used in MOSFETs, a Cu plug with a NiSi contact using Ta / TaN as a diffusion barrier is currently being considered. Conventionally, Ni was first deposited and then NiSi was formed, followed by the barrier and Cu deposition. In this study, Ti was employed as a barrier material and simultaneous formation of the NiSi contact and Cu plug / Ti barrier was attempted. Cu(100 nm) / Ti / Ni(20 nm) with varying Ti thicknesses were deposited on a Si substrate and annealed at $4000^{\circ}C$ for 30 min. For comparison, Cu/Ti/NiSi thin films were also formed by the conventional method. Optical Microscopy (OM), Scanning Probe Microscopy (SPM), X-Ray Diffractometry (XRD), and Auger Electron Microscopy (AES) analysis were performed to characterize the inter-diffusion properties. For a Ti interlayer thicker than 50 nm, the NiSi formation was incomplete, although Cu diffusion was inhibited by the Ti barrier. For a Ti thickness of 20 nm and less, an almost stoichiometric NiSi contact along with the Cu plug and Ti barrier layers was formed. The results were comparable to that formed by the conventional method and showed that this alternative process has potential as a formation process for the Cu plug/Ti barrier/NiSi contact system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.205-207
• /
• 2021

The way to develop an IoT device is to mount the sensor required by the application on a platform such as Arduino or Raspberry Pi, and write the sensor driver and application. At this time, if the driving driver for the sensor has already been written and the application can access the driver as a standardized API, then Plug&Play of the sensor will be possible. The old way to do this is because the sensor interface is too complicated to use on the current platform. In this paper, when a standardized sensor and driver with a USB terminal are plugged into the Raspberry Pi, we propose a method for automatically installing the driver. Application developers can get sensor values through Linux's file access API without worrying about sensor drivers. The proposed technique is currently being implemented on Raspberry-Pi.

• Journal of Bio-Environment Control
• /
• v.16 no.1
• /
• pp.27-31
• /
• 2007

The experiment has investigated the effects of blending rate of waste rockwool in nursery media on growth of Marygold 'Yellow boy' plug seedlings. A commercial plug medium containing 10% zeolite, 10% vermiculite, 5% perlite, 10% peatmoss and 65% cocopeat was used as the control, and the other media compounded with 10% of zeolite, vermiculite, perlite and peatmoss and 10, 30, and 50% of waste rock-wool. There was not significant difference in germination rate ot Marygold between treatments. Plant height, number of leaves, stem diameter and leaf area were higher in commercial plug medium and compound nursery media containing 50% of waste rockwool than 30 or 10% of waste rockwool. Fresh weight and dry weight of shoot and root increased in the treatment of commercial plug medium and the medium of 50% waste rockwool than 10 and 30% of waste rockwool. These results suggested the possibility of utilization of waste rockwool for medium components of plug seedlings.

• Journal of Korea Society of Industrial Information Systems
• /
• v.20 no.4
• /
• pp.47-54
• /
• 2015

With the spread of smart technology, in the personal and office equipment, many of the products are equipped with smart features. These changes have opened the era that can enforce the user's operation from a remote location. In this study, we design and implement a smart multi-plug system to make a multi-plug installed in the home can be operated anytime and anywhere via wireless network technologies add smart feature to a multi-plug that can be seen easily around us, it is intended to complement the limitations of traditional multi-plugs. The smart multi-plug proposed in this paper, by operating the plug remotely from smart devices at anytime and from anywhere, is possible to provide services required for the weak users such as elderly and children, it is expected that the proposed system are widely used in the various areas requiring remote control of the power supply including u-Farming, terrarium, and smart home, and so on.

• Tunnel and Underground Space
• /
• v.20 no.6
• /
• pp.446-454
• /
• 2010

CAES-G/T (Compressed Air Energy Storage - Gas Turbine) power generation is a likely option for the buffer facility stabilizing the fluctuation of the renewable powers, such as wind and solar powers. Considering the geological conditions, the underground CAES facility is most probable if the CAES-G/T generation is planed in Korea. In this kind of facility, a concrete plug is installed to seal the compressed air in the container, so that the selection of the shape and dimension of concrete plug could be a critical design factor. The stability evaluation of two types of plug was carried out by investigating the distribution of the factor of safety in the plugs and the distribution of contact pressure over the contact surface. The analysis result shows that the taper-shaped plug is more structurally stable than the wedge-shaped plug for the given geological condition. Possible separation of the rock-concrete interface around the spring line of the wedge-shaped plug is anticipated, which means the possible leakage of compressed air through the side wall and also means the poor mobilization of frictional resistance on that area.

• Transactions of Materials Processing
• /
• v.20 no.3
• /
• pp.250-256
• /
• 2011

Vacuum-assisted thermoforming is one of the critical steps for the successful application of film insert molding(FIM) to parts of complex shapes. If the thickness distribution of the formed film is non-uniform, cracking, deformation, warping, and wrinkling can easily occur at the injection molding stage. In this study, the effects of processing parameters, which include the film heating time, plug depth, plug speed and vacuum delay time, on film thickness distribution were investigated. It was found that the film thickness at the part sidewall decreases with increasing the film heating time and plug depth, but the thickness at the bottom was found to exhibit the opposite behavior. The film thickness of the sidewall was observed to increase at higher plug speed and vacuum delay time of 0 ~ 0.3sec.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.11 no.5
• /
• pp.287-298
• /
• 2016

This paper proposes an effective smart plug system capable of monitoring power, cutting off standby power and overload current. The key design concept is focused on measurement accuracy, self power consumption and controlling via smart phone application. The system is composed of several plugs and a hub, and adopts a star-topology-styled TDMA wireless protocol for communication between plug and hub. The test result shows that the implemented smart plug system meets K10026 regulation and is worth in electrical safety, energy saving, easy living.