• Restorative Dentistry and Endodontics
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• v.30 no.4
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• pp.344-351
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• 2005

This study compared the microshear bond strength $({\mu}SBS)$ to end and side of enamel rod bonded by four adhesives including two total etch adhesives and two self-etch adhesives. Crown segments of extracted human molars were cut mesiodistally. The outer buccal or lingual surface was used as specimens cutting the ends of enamel rods, and inner slabs used as specimens cutting the sides of enamel rods. They were assigned to four groups by used adhesives: Group 1 (All-Bond 2), Group 2 (Single Bond), Group 3 (Tyrian SPE/One-Step Plus), Group 4 (Adper Prompt L-Pop). After each adhesive was applied to enamel surface, three composite cylinders were adhered to it of each specimen using Tygon tube. After storage in distilled water for 24 hours, the bonded specimens were subjected to ${\mu}SBS$ testing with a crosshead speed of 1 mm/minute. The results of this study were as follows: 1. The $({\mu}SBS)$ of Group 2 $(16.50\pm2.31 MPa)$ and Group 4 $(15.83\pm2.33 MPa)$ to the end of enamel prism was significantly higher than that of Group 1 $(11.93\pm2.25 MPa)$ and Group 3 $(11.97\pm2.05 MPa)$ (p<0.05). 2. The $({\mu}SBS)$ of Group 2 $(13.43\pm2.93 MPa)$ to the side of enamel prism was significantly higher than that of Group 1 $(8.64\pm1.53 MPa)$, Group 3 $(9.69\pm1.80 MPa)$, and Group 4 $(10.56 \pm1.75 MPa)$ (p<0.05), 3. The mean $({\mu}SBS)$ to the end of enamel rod was significantly higher than that to the side of enamel rod in all group (p<0.05).

• Food Science of Animal Resources
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• v.29 no.6
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• pp.695-701
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• 2009

This study was performed to evaluate the effectiveness of biological critical control points using the genetic profile of Escherichia coli isolates from pork cutting plants. Samples were collected from carcasses, equipment (knife, table, glove, transport belt, boning and skinning machine), the environment (wall and floor), and meat cuts during the cutting process from two plants. Pulsed-field gel electrophoresis (PFGE) was used to characterize the E. coli isolates. An identical genotype was detected from the carcasses, equipment, environment, and final meat cuts, and showed that the incoming carcasses, which were contaminated during transportation from slaughterhouses, were a major source of E. coli that was spread throughout processing. Also, consistent cross-contamination due to improper cleaning and disinfection procedures was another possibility. As a result, incoming carcasses and cleaning procedures should be considered critical control points in pork cutting plants, since a heating step is not used to inactivate microorganisms. Furthermore, the high rate (59.6%) of E. coli isolation indicates E. coli can be a good indicator in livestock processing plants even though it has genetic diversity.

• Journal of the Korean Ceramic Society
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• v.31 no.2
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• pp.129-136
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• 1994

Si3N4 with 6w/o Y2O3 and 1.5w/o Al2O3 has been gas pressure sintered and its densification behavior and the effect of the sintering variables on the microstructure and mechanical properties were investigated. Densification rate was higher at temperature below 1775$^{\circ}C$ and between 187$0^{\circ}C$ and 195$0^{\circ}C$ than between 1775$^{\circ}C$ and 187$0^{\circ}C$. The faster densification at temperature between 187$0^{\circ}C$ and 195$0^{\circ}C$ was thought to be due to the increased amount of liquid phase resulting from the increased amount of Si3N4 dissolving in the liquid. $\beta$-Si3N4 and Y-disilicate at temperatures below 1775$^{\circ}C$, and only $\beta$-Si3N4 at 187$0^{\circ}C$ and above were detected by XRD analysis. Three different two-step schedules were employed to obtain sintered body with above 99% theoretical density and to investigate the effect of the sintering variables on the density, the microstructure and the mechanical properties of the sintered body. The sintered density did not change with the heating rate, and the microstructure became coarser as the temperature increased. The strength decreased with the width of $\beta$-Si3N4 grain, while the fracture toughness increased with the square root of it. A ceramic cutting tool made of the sintered body showed an uniform flank wear after the cutting test.

• Journal of the Korean Society of Costume
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• v.38
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• pp.289-304
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• 1998

In Korean clothing industry, most of the manufactures produce garments by subcon-tractors partially or entirely. It is very often that the design part is remote from production part and there is miscommunication between these two parts resulting dissatisfaction to both. Therefore it is very important to communicate the manufacturing information clearly and quickly to produce garments exactly the design part intended. Also to automate the clothing out how to produce and use the information objectively and efficiently. As a first step of moving to automation, the purpose of the research is to find out how manufacturing information and data are communicated in clothing manufacturing at present. In order to follow the information flow of a cer-tain manufacturer, the case study method was used. The case study samples were 12 clothing firms of 13 brands. The results and suggestions are as follows :- 1. A manufacturing information is communicated through paper documents such as“Production Order”, sample and patterns. At present, a production order sheet is the most efficient communication media, which comprises most of the information being communicated. 2. A manufacturing information comprises control information on the product, design in-formation, pattern information, cutting information, material information, sewing information, production schedule information, quality control information, costing information and information about the subcontractors. 3. A manufacturing is not quite objective except pattern information and cutting information which is presented by CAD systems. The communication of design information and sewing information should be somehow more objective. 4. There is not much information from a subcontractor. Considering that a subcontractor is the other partener of the communication, more information from the subcontractor is required for both benefit. 5. A designer produce most of the manufacturing information, but the information is communicated through a production manager to the subcontractor. The difference between the information maker and information communicator can cause any miscommunication. In future automated manufacturing, it will be possible for the designer to communicate to the manufacturer directly from the early stage of designing.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.1
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• pp.50-56
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• 2010

This paper presents a new design algorithm for piece-removing dynamical system, based on 6-Sigma DMADOV technique using ARIZ and Brainstorming. Our design target is the piece-removing system installed on a mobile platform of bead-grinding equipment. The 6-Sigma DMADOV technique guides us design process according to 6 steps, i.e., Define - Measure - Analyze - Design - Optimize - Verify. A Design strategy to reduce the weight of piece-removing dynamical system will be explored by using ARIZ, i.e.,(the abbreviation of Algorithm for Inventive Problem Solving in Russian). The ARIZ will result in a final solution that the height and angle control parts for a cutting tool should be replaced by a kinematical approach, rather than complicated mechatronic approach(using motors). The Optimize step is composed of two sub-steps: (i) Generating process for obtaining several ideas of piece-removing system by using Brainstorming technique, satisfying the final solution derived from the Design step using ARIZ, and (ii) Optimizing process for selecting the most optimal idea of piece-removing system by using Pugh's matrix from the viewpoints of weight, cost and accuracy. The laststep of Verify has shown that the final design obtained by the 6-Sigma DMADOV technique with ARIZ & Brainstormingcan improve an initial design with design requirements satisfied. In this paper, we have shown that ARIZ and Brainstorming can be cooperatively merged into 6-Sigma DMADOV to give us both a formulatedproblem-solving approach and diverse candidate solutions(or ideas) without trial-and-error efforts.

• Design & Manufacturing
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• v.11 no.3
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• pp.19-24
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• 2017

In these days, increase requirement of TEM (Transmission Electro Microscope) in not only scientific field but also industrial field. Because TEM can measure inner-structure of specimen a variety of materials like metal, bio. etc. When use TEM, specimen should be thin about 50nm. So making for thin specimen, use Ion milling device that include specimen holder. The holder generally made of Aluminium Aluminium holder is worn away easily. For this reason, using time of ion milling with aluminum holder is too short. To solve the problem, we replace aluminium holer to molybdenum alloy holder. In this paper, we design molybdenum alloy holer for CAM and modify CAD modeling for effective machining process. So we array a specimen 3 by 4 and setup orientation for one-shot machining process. Next we make a CAM program for machining. we making a decision two machining strategy that chose condition of tool-path method, step-down, step-over. etc. And then conduct machining using CNC milling machining center. To make clear difference between case.1 and case.2, we fixed machining conditions like feed-rate, main spindle rpm, etc. After machining, we confirm the condition of workpiece and analysis the problems case by case. Finally, case.2 work piece that superior than case.1 cutting with WEDM because that method can not ant mechanical effect on workpiece.

• Applied Chemistry for Engineering
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• v.26 no.6
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• pp.674-680
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• 2015

A solvent-soluble polyimide (PI) polymeric binder was synthesized by a two-step reaction for silicon (Si) anodes for lithium-ion batteries. Polyamic acid was first prepared through ring opening between two monomers, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA) and 4,4-oxydianiline (ODA), followed by condensation reaction. Using the synthesized PI polymeric binder (molecular weight = ~10,945), the coating slurry was then prepared and Si anode was fabricated. For the control system, Si anode based on polyvinylidene fluoride (PVDF, molecular weight = ~350,000) having the same constituent ratio was prepared. During precycling, PI polymeric binder revealed much improved discharge capacity ($2,167mAh\;g^{-1}$) compared to that of using PVDF polymeric binder ($1,740mAh\;g^{-1}$), while the Coulombic efficiency of two systems were similar. PI polymeric binder improved the cycle retention ability during cycles compared to that of using PVDF, which is attributed to an improved adhesion property inside Si anode diminishing the dimensional stress during Si volume changes. The adhesion property of each polymeric binder in Si anode was confirmed by surface and interfacial cutting analysis system (SAICAS) (Si anode based on PI polymeric binder = $0.217kN\;m^{-1}$ and Si anode based on PVDF polymeric binder = $0.185kN\;m^{-1}$).

• The Korean Journal of Applied Statistics
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• v.35 no.3
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• pp.407-419
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• 2022

The semiconductor fabrication process is complex and time-consuming. There are sometimes errors in the process, which results in defective die on the wafer bin map (WBM). We can detect the faulty WBM by finding some patterns caused by dies. When one manually seeks the failure on WBM, it takes a long time due to the enormous number of WBMs. We suggest a two-step approach to discover the probable pattern on the WBMs in this paper. The first step is to separate the normal WBMs from the defective WBMs. We adapt a hierarchical clustering for de-noising, which nicely performs this work by wisely tuning the number of minimum points and the cutting height. Once declared as a faulty WBM, then it moves to the next step. In the second step, we classify the patterns among the defective WBMs. For this purpose, we extract features from the WBM. Then machine learning algorithm classifies the pattern. We use a real WBM data set (WM-811K) released by Taiwan semiconductor manufacturing company.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.72-81
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• 2009

This paper presents quasi-resonant type high power factor ac power supply for atmospheric pressure plasma cleaning system adopting three phase PFC boost converter and it's control method. The presented ac power supply consists of single phase H-bridge inverter, step-up transformer for generating high voltage and three phase PFC boost converter for high power factor on source utility. Unlikely to the traditional LC resonant converter, the propose one has an inductor inside only. A single resonant takes place through the inside inductor and the capacitor from the plasma load modeled into two series capacitor and one resistance. The quasi-resonant can be achieved by cutting the switching signal when the load current decrease to zero. To obtain power control ability, the propose converter controlled by two control schemes. One is the changing output pulse period scheme in the manner of PFM(Pulse Frequency Modulation) control. On the other, to provide more higher power to load, the DC rail voltage is directly controlled by the 3-phase PFC boost converter. The significant merits of the proposed converter are the uniform power providing capability for high quality plasma generation and low reactive power in AC and DC side. The proposed work is verified through digital simulation and experimental implementation.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.42.1-42.1
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• 2016

The formation process and the dynamical properties of a large-scale quasi-circular flare ribbon were investigated using the SDO AIA and HMI data along with data from RHESSI and SOT. Within one hour time interval, two subsequent M-class flares were detected from the NOAA 12371 that had a ${\beta}{\gamma}{\delta}$ configuration with one bipolar sunspot group in the east and one unipolar spot in the west embedded in a decayed magnetic field. Earlier M2.0 flare was associated with a coronal loop eruption, and a two-ribbon structure formed within the bipolar sunspot group. On the other hand, the later M2.6 flare was associated with a halo CME, and a quasi-circular ribbon developed encircling the full active region. The observed quasi-circular ribbon was strikingly large in size spanning 650" in north-south and 500" in east-west direction. It showed the well-known sequential brightening in the clockwise direction during the decay phase of the M2.6 flare at the estimated speed of 160.7 km s-1. The quasi-circular ribbon also showed the radial expansion, especially in the southern part. Interestingly, at the time of the later M2.6 flare, the third flare ribbon parallel to the early two-ribbon structure also developed near the unipolar sunspot, then showed a typical separation in pair with the eastern most ribbon of the early two ribbons. The potential field reconstruction based on the PFSS model showed a fan shaped magnetic configuration including fan-like field lines stemming from the unipolar spot and fanning out toward the background decayed field. This large-scale fan-like field overarched full active region, and the footpoints of fan-like field lines were co-spatial with the observed quasi-circular ribbon. From the NLFF magnetic field reconstruction, we confirmed the existence of a twisted flux rope structure in the bipolar spot group before the first M2.0 flare. Hard X-ray emission signatures were detected at the site of twisted flux rope during the pre-flare phase of the M2.0 flare. Based on the analysis of both two-ribbon structure and quasi-circular ribbon, we suggest that a tether-cutting reconnection between sheared arcade overarching the twisted flux rope embedded in a fan-like magnetic field may have triggered the first M2.0 flare, then secondary M2.6 flare was introduced by the fan-spine reconnection because of the interaction between the expanding field and the nearby quasi-null and formed the observed large-scale quasi-circular flare ribbon.