• 한국CDE학회논문집
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• 제20권3호
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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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• 제40권2호
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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.

• 한국과학교육학회지
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• 제36권5호
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• pp.783-790
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• 2016

이 연구는 2009 개정 교육과정 5~6학년 과학 교과서에 새롭게 제시된 통합탐구 단원에 대한 초등학교 교사들의 인식과 지도 실태를 조사하여 통합탐구 단원 구성과 지도의 개선 방안을 모색하고자 하였다. 이를 위해 탐구지도와 관련된 기존 설문지를 수정, 보완하여 통합탐구 단원을 지도한 경험이 있는 교사들에게 설문을 실시해서 응답 내용을 분석하였다. 그 결과, 교사들은 통합탐구과정 지도의 중요성에 대해 긍정적으로 인식하고 있었다. '통합탐구능력 습득 및 발달, 과학 학습의 전이, 자유탐구 실행' 측면에서 교사들의 통합탐구 단원의 적용 효과에 대한 인식은 긍정적이었으며 그 이유로 '통합탐구과정 학습을 위한 별도의 시간 확보, 후속 학습에서의 활용, 자유탐구 활동에서 통합탐구과정 적용의 용이함'을 들었다. 반면에 교사들은 '통합탐구과정의 분절적 학습, 통합탐구 단원과 다른 단원 간의 연계성 부족, 학생의 호기심 유발이 어려운 교과서 내용 구성'을 이유로 통합탐구 단원의 효과에 대해 부정적인 의견을 제시하기도 했다. 또한 통합탐구 단원의 지도 실태에 대한 조사를 통해 많은 교사들이 통합탐구과정 지도 시 교과서 내용을 그대로 따르는 것을 확인하였다. 교사들이 통합탐구 단원 지도 시 어려움을 가장 크게 겪는 과정은 문제인식이었으며 그 다음으로 가설설정, 변인통제, 자료변환 및 자료해석, 일반화, 결론도출 순이었다. 교사들이 어려움을 겪는 이유는 '학생들의 호기심 경험 이해력 부족, 교사의 전문성 부족, 교과서 구성의 한계 및 학습 시간 부족' 등으로 나타났다. 이러한 연구 결과는 통합탐구 단원의 개선 및 통합탐구과정 지도 관련 교사 전문성 제고를 위한 노력이 필요함을 시사한다.

• 유기물자원화
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• 제21권2호
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• pp.63-70
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• 2013

현장 실규모의 다단공정으로 ATAD, EGSB 및 SBR을 조합한 HMUS 공정을 이용하여 돼지 축분 처리가능성을 시험하였다. 실험결과 고농도 유기물, 질소와 인의 제거에 효과적이었다. 각 오염항목의 시스템 공정별 처리효율이 ATAD 공정에서는 CODcr이 43.3%로 제일 높게 나타났다. 다음 단계인 응집침전 공정에서는 TS의 제거효율이 96.5%로 가장 높게 나타났다. 운전조건 중 OLR은 3-6Kg $COD/m^3{\cdot}day$ 및 선속도는 1.5-4 m/h의 범위일 때 평균 CODcr 제거 효율은 HRT 3일에서 가장 높게 나타났다. 유입수의 성상이 영향을 미치는 고온호기성 산화반응은 TS가 50,000 mg/L 이상 되어야 고온발열효과를 얻어 병원균을 사멸할 수 있는 온도를 얻었다. EGSB 공정을 거치는 동안 유기물제거량 당 발생된 가스발생량은 $2.3{\sim}8.5m^3/kgTS{\cdot}d$ (평균 $5.2m^3/kgTS{\cdot}d$)로 나타났다. 후처리단계인 간헐포기공정에서 전체운전기간 중 평균제거효율은 CODcr 71.7%, TS 64.1%, TN 45.9%, 및 TP 50.4% 로 나타났다.

• 소성∙가공
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• 제17권1호
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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.

• 임상간호연구
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• 제14권3호
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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.

• 한국CDE학회논문집
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• 제7권3호
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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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• 제9권5호
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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.

• 설비공학논문집
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• 제17권8호
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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.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 15TH KACG TECHNICAL MEETING-PACIFIC RIM 3 SATELLITE SYMPOSIUM SESSION 4, HOTEL HYUNDAI, KYONGJU, SEPTEMBER 20-23, 1998
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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.