• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.1
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• pp.46-52
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• 2012

Separate extraction of source ($R_S$) and drain ($R_D$) resistances caused by process, layout variations and long term degradation is very important in modeling and characterization of MOSFETs. In this work, we propose "Avalanche Hot-Source Method (AHSM)" for simple separated extraction of $R_S$ and $R_D$ in a single device. In AHSM, the high field region near the drain works as a new source for abundant carriers governing the current-voltage relationship in the MOSFET at high drain bias. We applied AHSM to n-channel MOSFETs as single-finger type with different channel width/length (W/L) combinations and verified its usefulness in the extraction of $R_S$ and $R_D$. We also confirmed that there is a negligible drift in the threshold voltage ($V_T$) and the subthreshold slope (SSW) even after application of the method to devices under practical conditions.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.3
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• pp.161-166
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• 1999

We investigate the device characteristics of the separated shorted-anode LIGBT (SSA-LIGBT), which suppresses effectively the negative differential resistance regime, by 2-dimensional numerical simulation. The SSA-LIGBT increases the pinch resistance by employing the highly resistive n-drift region as an electron conduction path instead of the lowly resistive n buffer region of the conventional SA-LIGBT. The negative differential resistance regime of the SSA-LIGBT is significantly suppressed as compared with that of the conventional SA-LIGBT. The SSA-LIGBT shows the lower forward voltage drop than that of the conventional SA-LIGBT.

• Restorative Dentistry and Endodontics
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• v.45 no.2
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• pp.14.1-14.7
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• 2020

Objective: The aim of this study was to perform a comparative evaluation of the effectiveness of ultrasonic tips versus the Terauchi file retrieval kit (TFRK) for the removal of broken endodontic instruments. Materials and Methods: A total of 80 extracted human first mandibular molars with moderate root canal curvature were selected. Following access cavity preparation canal patency was established with a size 10/15 K-file in the mesiobuccal canals of all teeth. The teeth were divided into 2 groups of 40 teeth each: the P group (ProUltra tips) and the T group (TFRK). Each group was further subdivided into 2 smaller groups of 20 teeth each according to whether ProTaper F1 rotary instruments were fractured in either the coronal third (C constituting the PC and TC groups) or the middle third (M constituting the PM and TM groups). Instrument retrieval was performed using either ProUltra tips or the TFRK. Results: The overall success rate at removing the separated instrument was 90% in group P and 95% in group T (p > 0.05) The mean time for instrument removal was higher with the ultrasonic tips than with the TFRK (p > 0.05). Conclusion: Both systems are acceptable clinical tools for instrument retrieval but the loop device in the TFRK requires slightly more dexterity than is needed for the ProUltra tips.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.2
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• pp.62-67
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• 2011

Launching tube is a kind of case to protect the guided weapons from external environments and conducted as a guide when they are fired. The guided weapons have been firmly kept at the launching tube and transferred, and would be separated at the required time when they are fired To meet the aim, it has been used explosive bolts which are reliable and efficient mechanical fastening devices having the special feature of a built-in release. The disadvantage of explosive bolt lies in that it is based on the high explosive effect of a pyrotechnic charge. When the explosive bolt is ignited, there are some bad effects; a flame, fragments and pyro-shock. Because of these bad effects there are many restriction to use bolt as joining devices to precision guided weapons. To solve these problems, the aim of the present work is to invent the ball-type separation bolt which is a pyrotechnically releasable mechanical linking device for two mechanical elements that does not suffer from such drawbacks. A standard pressure cartridge can moreover be easily integrated inside the device according to the present work and this with no modification to its structure. The present work was represented quantitatively the margin of separation safety and analysed separation mechanism in ball type separating bolt to perform the dynamic separation test.

• Journal of the Korea Fashion and Costume Design Association
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• v.19 no.4
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• pp.29-41
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• 2017

Because infants lack full communication skills and are not active main agents, nurturing and protection are essential. The value of smart devices that can help prevent potential threats and manage infant care is evaluated highly. This study offers basic research data that contributes to the development of devices for infant and parents as well as to future planning. This study compared and analyzed literature materials and visual materials based on news articles, advanced research, and official websites of brands. The research ranges and subjects are wearable devices for infants that were released or will be released between 2014 and 2017. Wearable devices that help protect and manage infant care are roughly separated into clothing, accessory, and the like. In this study, four kinds of clothing products, six kinds of accessories products, and fifteen kinds of other products were researched and a total of 25 kinds of products were analyzed. Categories was made in accordance with morphological characteristics, main features, materials and the design of wearable devices for infants depending on the device features. Wearable devices for infants that will be developed in the future must be based on a variety of suggestions in order to know best how to attach a sensor to an infant. From this study, the deduced trend analysis of wearable devices for infants can suggest new ways for follow-up studies as well as product development.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.8
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• pp.475-481
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• 2005

In the existing ICT technique, the mounted electronic devices on the printed circuit board are tested whether the devices are good or not by comparing and measuring the value of the devices after separating the devices to be tested from around it based on the guarding method. But, in case that resistance, inductor and capacitor are configured as a parallel circuit on the circuit pattern, values for each device can not be measured because the total impedance value of the parallel circuit is measured. Accordingly, it is impossible to test whether the parallel circuit is good or not in case that the measured impedance value is within the tolerance error. Also, it is difficult to identify that which device among R, L and C of the parallel circuit is bad in case that the measured impedance value is out of the tolerance error. Accordingly, this paper proposes a test method which can enhance the quality and productivity by separating and measuring accurately R, L and C components from the RLC parallel circuits on the device-mounted printed circuit board. First, the RLC parallel circuit to be test is separated electrically from around it using three-terminal guarding technique. And then R, L and C values are computed based on the total impedance values and phase angles between voltage and current of the parallel circuit measured from two AC input signals with other frequency, Finally, the availability and accuracy of the proposed test method is verified by reviewing the simulation results.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.2
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• pp.80-85
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• 2014

Side jet thruster using nozzle closure separation device provides a solid rocket with a trajectory shift function. Side jet thruster consists of low combustion temperature propellant, neutral type propellant grain and nozzle closure separation device. If a trajectory shift is required, side jet thrust is generated on the rocket by separating some nozzle closures located in the opposite direction to thrust. After completing trajectory shift, the other nozzle closures located in the thrust direction are separated to cease side jet thrust. The operation process is verified through ground static test. The result in this study can be applied to changing rocket trajectory by controlling side jet thrust through nozzle closure separation.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.1-8
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• 2015

Dual pulse rocket motor is a variant of solid rocket motor with two propellant grain separated by a pulse separation device. The major performance of such a rocket motor is influenced by the change in the hole area of pulse separation device to nozzle throat area ratio. In this study, we performed flow analysis to investigate the internal flow characteristics according to the pulse separation device hole area to nozzle throat area ratio change. Gases used flow analysis were used combustion gas of HTPB/AP composite propellant and nitrogen gas. Flow analysis results of the dual pulse rocket motor were validated by comparison with experimental results of pneumatics. Commercial CFD code ANSYS FLUENT 14.5 is used in this study to simulate flow analysis.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.62-70
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• 2002

The purpose of this paper in that users can use mobile device applications more easily and efficiently through MoDAM (Mobile Device Application Management) system. MoDAM automates the process of web retrieval for obtaining mobile device applications and the process of installing or updating it on mobile devices and then supply users with these automated services in a step form by combining two separated processes. We implement a web agent conforming to OSD (Open Software Description) specification for automating software retrieval and downloading and also a mobile device based software management module conforming to SyncML (Synchronization Markup Language) specification for synchronizing common data between server and client. The method of automated software retrieval and management for mobile devices using these standard specifications minimizes users' interrupts and also can be applied to traditional several different mobile devices, operating systems or downloading web sites without platform dependent considerations.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.170-174
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• 2008

Recently, a problem related to the thermal management in portable electronic and telecommunication devices is becoming issued. That is due to the trend of slimness of the devices, so it is not easy to find the optimal thermal management technology for the devices. From now on, a pressed circular type cooling device has been mainly used, however the cooling device with thin thickness is becoming needed by the inner space constraint. In the present study, the silicon and metal flat plate type cooling device with the separated vapor and liquid flow path was designed and fabricated. Through the experimental study, the normal isothermal characteristic by vapor-liquid phase change was confirmed and the cooling device with 70mm of total length showed 6.8W of the heat transfer rate within the range of $4{\sim}5^{\circ}C$/W of thermal resistance. In the meantime, the metal cooling device was developed for commercialization. The device was designed to have all structures of evaporator, vapor flow path, liquid flow path and condenser in one plate. And an envelope of that could be completed by combining the two plates of same structure and size. And the simplicity of fabrication process and reduction of manufacturing cost could be accomplished by using the stamping technology for fabricating large flow paths relatively. In the future, it will be possible to develop the commercialized cooling device by revising the fabrication process and enhancing the thermal performance of that.