• Korean Journal of Computational Design and Engineering
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• v.20 no.3
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• pp.312-319
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• 2015

The grinding and furbishing process as the finishing process for molds include the works such as the grinding, buffing, lapping and polishing among others. A finishing tool unit is applied to this finishing process for the burr, lapping, polishing and others of molds. A finishing tool unit can carry out the flexible machining, depending on the machining allowance for objects to be cut on the basis of the instrumental driving mechanism which enables the up, down, left and right floating, which is applied in link with the dedicated cutters and robot machining systems. This study selected the shape to increase the rotatory force of an impeller when air is discharged during the driving of a finishing tool unit, and reflected it to the impeller designing. In addition, the study analyzed each flow velocity and pressure distribution per air pressurization value and finally analyzed the rotating torque to suggest the optimal conditions in designing impellers.

• East Asian mathematical journal
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• v.40 no.2
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• pp.209-229
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• 2024

In this study, we design a teaching unit that constructs Pascal graphs and extended Pascal triangles to explore number patterns inherent in them. This teaching unit is designed to consider the diachronic process of teaching-learning by combining Dörfler's theoretical generalization model with Wittmann's design science ideas, which are applied to the didactical practice of mathematization. In the teaching unit, considering the teaching-learning level of prospective teachers who studied discrete mathematics, we generalize the well-known Pascal triangle and its number patterns to extended Pascal triangles which have directed graphs(called Pascal graphs) as geometric models. In this process, the use of symbols and the introduction of variables are exhibited as important means of generalization. It provides practical experiences of mathematization to prospective teachers by going through various steps of the generalization process targeting symbols. This study reflects Wittmann's intention in that well-understood mathematics and the context of the first type of empirical research as structure-genetic didactical analysis are considered in the design of the learning environment.

• Journal of The Korean Association For Science Education
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• v.36 no.5
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• pp.783-790
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• 2016

The 'Integrated Inquiry' unit is a new addition in the 5th~6th grade science textbooks, and was developed for the 2009 revised national curriculum. The unit deals with six integrated inquiry process skills: problem cognition, formulating hypotheses, controlling variables, transforming and interpreting data, drawing results, and generalization. The purpose of this study is to investigate the perceptions and the teaching practices of elementary school teachers on this unit in their school curriculum and where improvements can be made. Data was collected from questionnaires filled out by 92 elementary school teachers. The results are as follows: First, teachers do have a positive perception on the importance of teaching integrated process skills. Second, with that being true, this unit ended up receiving both positive and negative reviews by teachers. This research found that there were good and bad responses on the educational aspects of this unit in three particular areas: dealing with the development of integrated inquiry process skills, facilitating science learning in other units, and implementing open inquiry. Third, teachers have difficulties particularly in problem cognition, formulating hypotheses, controlling variables, transforming and interpreting data, generalization, and drawing results. There is a lack of student understanding as well as a lack of professionalism for teachers on this unit, and many issues related to the composition of the textbook. This study may have important implications for making improvements in this unit and teaching integrated process skills.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.2
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• pp.63-70
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• 2013

Experiments in a pilot-scale hybrid multi-stage unit system (HMUS) combination of ATAD and EGSB followed by SBR process for pig slurry treatment were conducted to demonstrate the feasibility of using autothermal thermophilic aerobic digestion (ATAD) and expended granular sludge bed (EGSB) followed by sequencing batch reactor (SBR) system. Contaminants in pig slurry with high organic matter, nitrogen (N) and phosphorus (P) content were completely removed in the combined process. The highest removal rate for CODcr among contaminants in the feed pig slurry was attained by about 43.3% in ATAD unit process. Also TS removal rate of 96.5% was attained and the highest in the next coagulation unit process. The highest removal rate of CODcr under operating parameter conditions of OLR(organic loading rate), 3-6Kg $COD/m^3{\cdot}day$ and line velocity, 1.5-4m/h was earned at 3days of HRT. The disinfection of pathogens was effective at 50,000mg/L of TS in ATAD unit process. Biogas production per organic removal was $2.3{\sim}8.5m^3/kgTS{\cdot}d$ (average $5.2m^3/kgTS{\cdot}d$) in EGSB unit process. The average removal rates of CODcr 71.7%, TS 64.1%, TN 45.9%, and TP 50.4% were earned in the intermittent aeration SBR unit process.

• Transactions of Materials Processing
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• v.17 no.1
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• pp.27-34
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• 2008

In order to manufacture a doubly curved sheet metal, the incremental roll forming process which adopts advantages such as the flexibility of the incremental forming process and continuous bending deformation of the roll forming process has been experimentally investigated. An experimental equipment was developed which was named as unit roll set (URS) consisting of two pairs of support rolls and an upper center roll. The upper roll equipped with the servo control unit is motor-driven and can be positioned in the vertical direction according to the user's commands. Four support rolls are idle, and they freely rotate only along the axis so as to transfer the plate more stably in the tangential direction of the rotation of the driving roll. In the process, the plate is deformed incrementally as deformation proceeds simultaneously in longitudinal and transverse directions. Through the experiments using URS, information regarding to forming schedules is found out to fabricate curved hull plates. This study demonstrates the further application of the incremental roll forming process in shipbuilding industries.

• Journal of Korean Clinical Nursing Research
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• v.14 no.3
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• pp.141-151
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• 2008

Purpose: This study aimed at applying a standardized nursing process to adult surgery patients of post anesthetic care unit, and examining the validity of linkages in the measuring index of nursing outcome by which nursing outcome was applied. Method: The subjects were 184 surgery adult patients admitted at the post anesthetic care unit of Y university hospital. This study was used the measured tool developed by Choi et al.(2004) and by Lee (2004) who had already verified a validity based on Johnson and Bulechek's study(2001). Results: The nursing diagnosis of an acute pain, an urinary retention, a nausea, a decreased cardiac output, an ineffective airway clearance and an ineffective airway clearance were used in taking care for patients. The related factors according to the main nursing diagnosis were as the following: an injurious physical factor in an acute pain, reflex are inhibition in an urinary retention, post surgical anesthesia in a nausea, stroke volume change in a decreased cardiac output, secretory stasis in an ineffective airway clearance, pain in an ineffective breathing pattern. Conclusion: The study results could be facilitated in nursing process application for nurses at post anesthetic care unit. Also this study would provide basic data to develop a computerized program for the improvement of nursing process application.

• Korean Journal of Computational Design and Engineering
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• v.7 no.3
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• pp.148-156
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• 2002

Most Rapid Prototyping (RP) processes adopt a solid Computer Aided Design (CAD) model, which will be sliced into thin layers of constant thickness in the building direction. Each cross-sectional layer is successively deposited and, simultaneously, bonded onto the previous layer; and eventually the stacked layers from a physical part of the model. A new RP process, the transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), has been developed to reduce building time and to improve the surface finish of parts with the thick layers and a sloping surface. This paper describes the generation of Unit Shape Layer (USL), the cutting path data of the linen. hotwire cutter for the VLM-ST process. USL is a three-dimensional layer with a thickness of more than 1 mm and a side slope, and it is the basic unit of cutting and building in the VLM-ST process. USL includes data such as layer thickness, positional coordinates, side angles of each layer, hotwire cutting speed, the heat input to the hotwire, and reference shape. The procedure of generating USL is as follows: (1)Generation of the mid-slice from the CAD model, (2)Conversion of the mid-slice into a simply connected domain, (3)Generation to the reference shape for the mid-slice, (4)Calculation of the rotation angle of the hotwire of the cutting system.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.613-618
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• 1999

L-Proline-producing mutant strains were developed by exposing L-glutamic acid-producing bacteria to N-metyl-N-nitro-nitrosoguanidine and UV irradiation. A L-histidine auxotroph of Corynebacterium acetoacidophilum RYU3161(KCTC 0616BP), which was resistant to sulfaguanidine and proline analogs (DHP, AZC, TAC), was isolated. The activity of the mutant strain's $\gamma$-glutamyl kinase was 45% higher than that of the parent strain. The optimum level of L-histidine for production of L-proline was 0.16 g/l. In a 5-1 jar fermenter, the mutant strain produced L-proline at a high concentration (35 g/l) level within 48 h of cultivation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.8
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• pp.704-713
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• 2005

The purpose of this study is to suggest the concept of an integrated unit and to develop integrated units considering the layout of luminaires and diffusers in workspace. An integrated unit can be defined as a planning unit which satisfies the environment comfort criteria of workspace. Integrating process of each unit was proposed by considering the current workspace planning process. Luminaire and diffuser types are classified by surveying the workspace of the domestic and foreign office buildings. Several lighting units and air-conditioning units were developed by visual and thermal simulation, and integrated units for various architectural module which satisfies the visual and thermal comfort criteria were drawn from those units.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.09a
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• pp.33-33
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• 1998

Invisible charged clusters are suggested to form in the gas phase and to become the growth unit in the thin film process. Similar suggestion had been made by Glasner el al. in the crystal growth of KBr and KCL in the solution where the lead ions were added. The charged cluster model, which was suggested in the diamond CVD process by our group, will be extended to the other thin film processes. It will be shown based on both the theoretical analysis and the experimental evidences that the charged clusters are formed in the gas phase and become the growth unit of the crystal in the thin film process.