• Journal of Korean Society of Water and Wastewater
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• v.16 no.6
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• pp.717-725
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• 2002

A bench-scale submerged-type membrane filtration system (SMFS) was constructed to study a feasibility of membrane filtration for solid-liquid separation in water and wastewater treatment processes. In the case of applying the SMFS to a biological wastewater treatment process, so-called membrane bioreactor, aeration underneath membrane modules is usually employed in order to provide oxygen demand for microbial growth as well as to control membrane fouling. A study was investigated the effects of operation parameters by aeration intensity, feed concentration, foulant type and airlift pore size on critical flux. Critical flux tends to increase with aeration rate. Optimal aeration flow rate was found to be 10 L/min/module. Feed concentration and foulant type has a significant effect on membrane fouling and filtration performance. But downward position and pore size of airlift has no a significant effects on membrane fouling and filtration performance.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.85-92
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• 2022

In the case of incumbent training, unlike training for the unemployed, it is difficult to show the results of training. In this study, factors affecting the performance of vocational competency development training were selected and the main factors were derived. Data were collected through Focus Group Interview(FGI), and regression analysis was performed through factor analysis and reliability analysis. As a result, empathy, training participation type, reliability, working experience, and training operation type were derived as factors affecting job satisfaction. did. Confidence and training participation patterns were derived as factors affecting training satisfaction, and the results showed that the larger the variable, the more positive it was. Therefore, as factors affecting the vocational competency development training performance, there are empathy, training participation type, reliability, work experience, training operation type, certainty, and training participation type. It was confirmed that the results had an effect.

• Journal of Chest Surgery
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• v.14 no.1
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• pp.26-32
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• 1981

Three cases of tricuspid atresia were treated by Fontan varieties of operation in this department in 1980. The first case was 19 year old girl who underwent Glenn operation at the age of 6 years. Her second operation was done with ASD closure and 16mm Ionescu-Shiley valved conduit insertion between right atrium and main pulmonary artery. The second case was a 5 year old boy who underwent Kreutzer operation successfully utilizing 14mm Ionescu-Shiley va]ved conduit. The above mentioned 2 cases were Type Ib after Keith`s classification, whose immediate postoperative courses were complicated by pleura] effusion [in 2nd case chylothorax] hepatomegaly, and ascites. Those complications were relieved completely by medical treatment and closed thoractomy; Postoperative follow-up up to 11 months and 1 year periods were satisfactory with disappearance of cyanosis and dyspnea. The third case was a 8 year old boy who had complete TGA with TA [Keith`s Type IIb] who underwent Kreutze`s operation utilizing 14mm Ionescu-Shiley valved conduit, he died of low cardiac output Immediately after open heart surgery.

• Journal of Sensor Science and Technology
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• v.30 no.1
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• pp.61-65
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• 2021

In this study, we propose a 2500 frame per second (fps) high-speed binary complementary metal oxide semiconductor (CMOS) image sensor using a gate/body-tied (GBT) p-channel metal oxide semiconductor field effect transistor-type high-speed photodetector. The GBT photodetector generates a photocurrent that is several hundred times larger than that of a conventional N+/P-substrate photodetector. By implementing an additional binary operation for the GBT photodetector with such high-sensitivity characteristics, a high-speed operation of approximately 2500 fps was confirmed through the output image. The circuit for binary operation was designed with a comparator and 1-bit memory. Therefore, the proposed binary CMOS image sensor does not require an additional analog-to-digital converter (ADC). The proposed 2500 fps high-speed operation binary CMOS image sensor was fabricated and measured using standard CMOS process.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.6
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• pp.529-536
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• 2010

Purpose: The Purpose of this study is to show the total survival rate of implants with maxillary sinus grafting and the effects that reach the survival rate by classifying types of graft materials, implant type, operation method, residual bone height and evaluate graft material resorption rate after sinus grafting Patients and Methods: 61 dental implants placed with sinus bone grafting in 24 patients at Wonkwang University Sanbon Dental Hospital were installed simultaneously or after regular healing. Various bone grafts (autograft, xenograft, allograft, alloplast) and fourth implant type (GSII, Xive, Implantium, Novel biocare) were used. All implants were investigated clinically and radiographically, being with average 20 months follow-up period after installation. Results: 3 fixtures were lost, resulting in 95.1% cumulative survival rate of 61 osseointegrated dental implant. Survival rate according to bone material type, Implant type, operation method, residual bone height, have no statistically significant differencies. The mean preoperative residual alveolar bone height was 4.75 mm, average postoperative height of graft materials 10.8 mm, vertical bone resorption rate was 10% after 2 years. Resorption rate according to operation method was 7% (simultaneous) and 5% (delayed) after 1 year. Conclusion: It can be suggested that maxillary sinus grafting may have predictable result with various bone graft materials and implant type, residual bone height, operation method

• Journal of Astronomy and Space Sciences
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• v.29 no.2
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• pp.221-232
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• 2012

We analyzed the manufacturing procedure, specifications, repair history, and details of celestial movements of the water-hammering type $Honsang$ (celestial globe). Results from our study on the remaining $Honsangs$ in China and Japan and on the reconstruction models in Korea were applied to our conceptual design of the water-hammering type $Honsang$. A $Honui$ (armillary sphere) and $Honsang$ using the water-hammering method were manufactured in $Joseon$ in 1435 (the 17th year of King $Sejong$). $Jang$ $Yeong-Sil$ developed the $Honsang$ system based on the water-operation method of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China. Water-operation means driving water wheels using a water flow. The most important factor in this type of operation is the precision of the water clock and the control of the water wheel movement. The water-hammering type $Honsang$ in $Joseon$ probably adopted the $Cheonhyeong$ (天衡; oriental escapement device) system of $Shui$ $y{\ddot{u}}n$ $i$ $hsiang$ $t'ai$ in China and the overflow mechanism of $Jagyeongnu$ (striking clepsydra) in $Joseon$, etc. In addition to the $Cheonryun$ system, more gear instruments were needed to stage the rotation of the $Honsang$ globe and the sun's movement. In this study, the water-hammering mechanism is analyzed in the structure of a water clock, a water wheel, the $Cheonhyeong$ system, and the $Giryun$ system, as an organically working operation mechanism. We expect that this study will serve as an essential basis for studies on $Heumgyeonggaknu$, the water-operating astronomical clock, and other astronomical clocks in the middle and latter parts of the $Joseon$ dynasty.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.73-78
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• 2010

Purpose: The purpose of this study is to analyze the clinical and radiological results of minimally invasive percutaneous screw fixation in intra-articular calcaneal fractures and its complications. Materials and Methods: This study is based on 30 intra-articular calcaneal fractures that treated by index operation from June 2005 to November 2006 with at least 6 months follow-up. We assessed the clinical and radiological outcomes and complications. Results: According to Sanders classification, there were 8 in type IIA, 7 in type IIB, 3 in type IIIAB, 6 in type IIIBC, 6 in type IV. And according to Essex-Lopresti classification, there were 9 in the tongue type, 21 in the joint depression type. Average follow-up period was 14.6 months (range: 6-23 months). Average interval between from injury to operation was 2.3 days. Average AOFAS score was 87.7 (range: 52-92). Satisfactory results were obtained in 22 cases (73.3%) by AOFAS score and in 20 cases (66.7%) by VAS score (mean: 3.4). Radiological results improved from 8.7 to 20.3 degrees in the Bohler angle and from 40.2 mm to 52.1 mm in calcaneal height. Postoperative complications were 2 skin and soft tissue problems and 1 sural neuropathy. Conclusion: Minimally invasive percutaneous screw fixation may be useful alternative surgical method in the management of Sanders type II and III calcaneal fractures, which is possible to achieves the anatomical restoration and minimizes postoperative complication in patients with high risks of soft tissue compromise and allows relatively early operation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.363-369
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• 2005

we compared the operating characteristics between flux-lock type and resistive type superconducting fault current limiters(SFCLs). Flux-lock type SFCL consists of two coils, which are wound in parallel each other through an iron core, and a high-Tc superconducting(HTSC) element is connected with coil 2 in series. The the flux-lock type SFCL can be divided into the subtractive polarity winding and the additive polarity winding operations according to the winding directions between the coil 1 and coil 2. It was confirmed from experiments that flux-lock type SFCL could improve both the quench characteristics and the transport capacity compared to the resistive type SFCL, which means, the independent operation of HTSC element.

• Journal of the Korean Statistical Society
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• v.36 no.2
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• pp.201-208
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• 2007

Evolutionary operation (EVOP) proposed by Box (1957) is a method for continuous monitoring and improvement of a full-scale manufacturing process with the objective of moving the operating conditions toward the better ones. EVOP consists of systematically making small changes in the levels of the two or three process variables under consideration. Data are collected on the response variable at each point of two level factorial design with the center point and a cycle is said to have been completed. The cycles are replicated sequentially until the decision is made on whether further cycle of experiments is needed to conclude the significance of any of main effects or interaction effects or the curvature. In this paper, an improved flow chart of EVOP is proposed and how to determine the number of cycles is studied based on the size of type II error. In order to reject the alternative hypothesis of interests with more confidence and conclude that we believe in the null hypothesis of no effects, we propose a counter measure $p^*-value$ corresponding to the p-value. The relationship of $p^*-value$ to the probability of type II error ${\beta}$ under the alternative hypothesis of interests is analogous to that of p-value to the probability of type I error ${\alpha}$. Also the implementation of EVOP with a mixture experiment is discussed.

• Journal of Electrical Engineering and Technology
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• v.3 no.4
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• pp.546-551
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• 2008

In this paper, a flux-lock type superconducting fault current limiter(SFCL) integrated with a voltage-controlled voltage source inverter(VC-VSI) is proposed. The suggested equipment, which consists of a flux-lock type SFCL and a VCVSI, can perform the fault current limiting operation from the occurrence of a short-circuit. In addition, it can compensate the reactive power that the non-linear load requires and also perform the uninterruptible power supply(UPS) as well as the load voltage stabilization by controlling the amplitude and the phase of the inverter's output voltage. The specification for a test model was determined and its various functions such as the fault current limiting and the power conditioning operations were presented and analyzed via computer simulation. Through the analytical results based on the computer simulation, the validity of the analysis was confirmed and its multi-operation was discussed.