• Journal of dental hygiene science
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• v.13 no.3
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• pp.330-338
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• 2013

In order to explore microleakage in class V cavity based on different kinds of several dentin adhesive and composite resin, 2 kinds of composite resin was restored and exposed after applying 4 kinds of dentin adhesives. Deposited in methylene blue solution for 4 hours and cut in parallel with tooth longitudinal axis. By observing dye penetration level of enamel and dentin margins of each restored resin following conclusion was obtained. 1. In composite resin Filtek Z350XT Universal (3M/ESPE Dental Products, USA) in enamel margin, Easy Bond (3M/ESPE Dental Products) showed the lowest microleakage and this leakage was represented to be high in the order of Single Bond 2 (3M/ESPE Dental Products), Scotchbond Multi-Purpose (3M/ESPE Dental Products) and Cearfil SE Bond (Kuraray Medical Inc., Japan). In case of Filtek Z350XT Flowable (3M/ESPE Dental Products), Scotchbond Multi-Purpose showed the lowest microleakage and this leakage was represented to be high in the order of Single Bond 2, Clearfil SE Bond and Easy Bond. 2. In case of Filtek Z350XT Universal in dentin margin, Easy Bond showed the lowest microleakage and this leakage was represented to be high in the order of Scotchbond Multi-Purpose, Single Bond 2 and Clearfil SE Bond. In case of Filtek Z350XT Flowable, Scotchbond Multi-Purpose and Single Bond showed the lowest microleakage and this leakage was represented to be high in the order of Clearfil SE Bond and Easy Bond. 3. In all the groups excepting S-U group (Single Bond 2+Filtek Z350XT Universal), enamel margin showed more higher microleakage than that of dentin margin. 4. There was a difference between enamel and dentin margin among each group but it was not significant statistically (p>0.05). When summarizing this result, it is considered that composite resin and dentin adhesive could be applied selectively and particularly in case of applying 1-step self-etching dentin adhesive, this method would be advantageous for manipulation convenience and shortening of operation time.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.67-73
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• 2019

In this study, to optimize the production and utilization of biogas for organic waste resources, the precision monitoring of on-site facilities and the energy balance by facility were analyzed, and the solutions for field problems were investigated, and the design and operation guidelines for pretreatment facilities and generators were presented. Gas pre-treatment is required to solve frequent failures and efficiency degradation in operation of high quality refining facilities, and processing processes such as desulfurization, dehumidification, deoxidization, dust treatment, volatile organic compounds, etc. Since these processes are substances that are also eliminated from the high-quality process, quantitative guidelines are not presented in the gas pretreatment process, but are suggested to operate during the processing process as a qualitative guideline. In particular, dust, siloxane, and volatile organic compounds are the main cause of frequent failure of high-quality processes if they are not removed from the gas pretreatment process. Design of the biogas high-quality process. The operation guidelines provide quality standards [Methane content (including propane) of 95% or more] with 90% or more utilization of the total gas generation, two systems, and a margin of 10% or more. It also proposed installing gas equalization tank, installing thermal automatic control system for controlling equalization of auxiliary fuel, installing dehumidification device at the back of high quality for removing moisture generated in the process of gas compression, installing heat-resisting facilities to prevent freezing of facilities in winter and reducing efficiency, and installing membrane facilities in particular.

• Archives of Reconstructive Microsurgery
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• v.20 no.2
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• pp.89-95
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• 2011

Purpose: The purpose of this study was to evaluate the clinical results of anterolateral thigh free flap on soft tissue defect following wide excision in malignant soft tissue tumor of lower extremities. Methods: Between February 2005 to April 2010, we followed up 19 cases who were undergoing anterolateral thigh free flap because of soft tissue defect following wide excision of malignant soft tissue tumor in lower extremity, including 9 cases were heel, 5 cases in foot, 3 cases in ankle, 2 cases in knee and leg. We observed that of implanted area's color, peripheral circulation at 3, 5, 7 days after operation and evaluated operating time, amount of hemorrhage, implanted skin necrosis, additional operations, complications. And we also evaluated the oncologic results, including local recurrence, metastasis, and morbidity. Results: Average operation time of wide excision and anterolateral thigh free flap was 7 hour 28 minutes. 18(94.7%) of total 19 cases showed successful engraftment, on the other hand, failure of engraftment due to complete necrosis of flap in 1 case. In 18 cases with successful engraftment, reoperation was performed in 4 cases. Among them, removal of hematoma and engraftment of flap after bleeding control was performed in 3 cases, because of insufficient circulation due to the hematoma. In the remaining 1 case, graft necrosis due to flap infection was checked, and grafted after combination of wound debridement and conservative treatment such as antibiotics therapy, also skin graft was performed at debrided skin defect area. Skin color change was mainly due to congestion with hematoma, flap was not observed global congestion or necrosis except 4 cases which shows partial necrosis on margin that treated with conservative therapy. Conclusions: Anterolateral thigh free flap could be recommended for reconstruction of soft tissue defect following wide excision of malignant soft tissue tumor in lower extremity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.18-29
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• 2015

The purposes of this research and development are as follows: first, to provide pleasant driving environments inside tunnels; second, to improve the current illumination environments lacking in diffusion luminance meters to meet tunnel lighting standards; and, third, to reduce the consumption of tunnel lighting energy accounting for approximately 65% of tunnel maintenance costs because of inadequate visual environments and tunnel operations. Further details are listed below. Firstly, an image luminance meter for tunnels that can implement the L20-method which is a tunnel luminance method that follows the international standards of CIE88, which was developed in order to improve and change the existing illumination-based tunnel lighting operation system to a luminance-based system. (The margin of error of below 5% according to the results of a test by an authorized agency and field test). Secondly, early illumination control is possible since the lighting control system that can be operated based on luminance enables interlocking control of the inside and outside of a tunnel using ethernet communication. Thirdly, guidelines for field application of the system are proposed. In addition, the luminance inducers of tunnels are found and the reflexibility of each facility that may reduce luminance of the boundaries is also proposed. Fourthly, as a result of a test bed, power consumption of luminance-based lighting operations decreased by 15.6% compared to illumination-based operations. Applying the feedback controls and maintenance factors of internal/external luminance meters, it reduced by 36.4%. Therefore, we became able to provide a luminance-based lighting operation system that complies with tunnel lighting design standards and provides a visual environment for drivers.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.2
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• pp.128-133
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• 2008

Phase-change random access memory (PRAM) chip cell phase of amorphous state is rapidly changed to crystal state above 160 Celsius degree within several seconds during Infrared (IR) reflow. Thus, on-board programming method is considered for PRAM chip programming. We demonstrated the functional 512Mb PRAM with 90nm technology using several novel core circuits, such as metal-2 line based global row decoding scheme, PN-diode cells based BL discharge (BLDIS) scheme, and PMOS switch based column decoding scheme. The reverse-state standby current of each PRAM cell is near 10 pA range. The total leak current of 512Mb PRAM chip in standby mode on discharging state can be more than 5 mA. Thus in the proposed BLDIS control, all bitlines (BLs) are in floating state in standby mode, then in active mode, the activated BLs are discharged to low level in the early timing of the active period by the short pulse BLDIS control timing operation. In the conventional sense amplifier, the simultaneous switching activation timing operation invokes the large coupling noise between the VSAREF node and the inner amplification nodes of the sense amplifiers. The coupling noise at VSAREF degrades the sensing voltage margin of the conventional sense amplifier. The merit of the proposed sense amplifier is almost removing the coupling noise at VSAREF from sharing with other sense amplifiers.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.136-142
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• 2013

CRC features have been added to increase the reliability of the data in memory products for high-speed operation, such as DDR4. High-speed memory products in a shortage of internal timing margin increases for the CRC calculation. Because the existing CRC requires many additional circuit area and delay time. In this paper, we show that the matrix-type CRC and a new XOR/XNOR gate could be improved the circuit area and delay time. Proposed matrix-type CRC can detect all odd-bit errors and can detect even number of bit errors, except for multiples of four bits. In addition, a single error in the error correction can reduce the burden of re-transmission of data between memory products and systems due to CRC errors. In addition, the additional circuit area, compared to existing methods can be improved by 57%. The proposed XOR gate which is consists of six transistors, it can reduce the area overhead of 35% compared to the existing CRC, 50% of the gate delay can be reduced.

• Journal of Energy Engineering
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• v.13 no.1
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• pp.60-67
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• 2004

The recent movement to deregulated and competitive electricity market reacquires new concepts against existing central dispatch in the system operation and pinning. As power systems tend to be operated more closely to their ultimate ratings, the role of SCOPF (Security Constrained Optimal Power flow) is changed and the importance for real-time security inhancement will be more increased i]1 the new and com partitive electricity market. This paper deals with the application of the SCOPF which makes possible the On-Line application. The security margin of power system truly is changed according to the conditions or configuration of power systems, therefore, the sensitivity factor reiated to the security is recalculated and the application should be updated in accordance with the state of power system. The goal of this paper is to obtain proper security through the effluent usage of the sensitivity and to apply this a1gorithm to system operation. The proposed mechanism has been tested on a sample system and the results show more secure conditions against critical contingencies.

• Journal of Advanced Navigation Technology
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• v.20 no.4
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• pp.292-297
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• 2016

Since continuous descent operations (CDO) is one of several tools available to aircraft operators and air navigation service providers (ANSPs) to increase safety, flight predictability, and airspace capacity while reducing noise, controller-pilot communications, fuel burn and emissions, widespread implementation of CDO would result in significant reductions in the environmental impact and aircraft operation costs in south korea as well. After analyzing each procedure from standard terminal arrival routes used for the Incheon international airport, it can be noticed that one of the procedures has a relatively high altitude constraint at initial approach fix than others, which lead the pilots to use unnecessary drag device in certain situations. Therefore we came to a conclusion that some arrival procedures need to be revised, so unnecessary procedure required during approach can be minimized, thereby reducing fuel consumption, noise and emissions compared to current approach procedures. And it is going to increase the safety margin significantly during approach phase due to reduced workload.

• Archives of Plastic Surgery
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• v.35 no.5
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• pp.581-588
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• 2008

Purpose: It is generally accepted that anatomical structures of the soft tissue in Asian faces are quite different from those in Caucasian. It is presumed that these differences are due to collagen rich thick dermis and durable superficial musculo-apponeurotic system (SMAS) in Asian. We classified the aging lower eyelids and reviewed the operative procedures according to the types of aging lower eyelids in Asian. Methods: We compared preoperative and postoperative photos of 117 patients over 30 years of age, who underwent lower blepharoplasty at the Kyunghee Medical Center from January 2001 to April 2006. We classified the patients based on the degree of skin laxity, presence of nasojugal groove and malar bag, the extent of aging process. We also reviewed the operative procedures according to each type of classification. Results: We classified our patients into four types as following. Type I patients showed minimal skin-muscle excess confined to lower eyelids regardless of the facial line. For these patients, we performed only transcutaneous or transconjunctival blepharoplasty. In type II patients, nasojugal grooves were shown and skin- muscle laxity was limited to the medial side of imaginary vertical line at lateral margin of pupil. In these cases, we performed free fat graft or fat repositioning on nasojugal groove or fat removal and septal duplication confined to medial side. Type III patients displayed more advanced medial bulging and remarkable laxity over the lateral side, the same operation methods as those of type II were applied at the lateral side of the line. Type IV patients demonstrated extensive midfacial aging changes including malar bags and underwent superficial subciliary cheek lift. Conclusion: The lower eyelid aging of Asian is different from those of Caucasian. We think that our classification is useful in selection of appropriate operative procedure to address specific problems for Asian patients.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.1950-1957
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• 2015

Modern wind generators (WGs) are forced or encouraged to participate in frequency control in the form of inertial and/or primary control to improve the frequency stability of power systems. To participate in primary control, WGs should perform deloaded operation that maintains reserve power using speed and/or pitch-angle control. This paper proposes an optimization formulation that allocates the required reserve to WGs to maximize the kinetic energy (KE) stored in a wind power plant (WPP). The proposed optimization formulation considers the rotor speed margin of each WG to the maximum speed limit, which is different from each other because of the wake effects in a WPP. As a result, the proposed formulation allows a WG with a lower rotor speed to retain more KE in the WPP. The performance of the proposed formulation was investigated in a 100-MW WPP consisting of 20 units of 5-MW permanent magnet synchronous generators using an EMTP-RV simulator. The results show that the proposed formulation retains the maximum amount of KE with the same reserve and successfully increases the frequency nadir in a power system by releasing the stored KE in a WPP in the case of a disturbance.