• 영재교육연구
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• 제18권3호
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• pp.465-496
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• 2008

21세기 지식기반사회에서 창의성은 리더십 및 전문성과 더불어 인재의 핵심가치로 부각되고 있다. 창의성은 영재성의 주요한 요소이며, 영재교육에서 창의성 계발은 프로그램의 핵심이다. 특히 고차원의 사고력과 이해를 요구하는 수학영역에서의 창의성은 사고의 융통성을 잴 수 있는 척도로 창의성 연구의 기초 도구로 쓰인다. 그러나 수학 창의성에 대한 이론적 연구는 많지 않다. 본 논문에서는 Sternberg와 Lubart가 제안한 6가지의 창의성 접근, 즉 신비주의적 접근, 실용주의적 접근, 심리-역등적 접근, 심리-측정적 접근, 인지적 접근, 사회-성격적 접근에 따라 수학 창의성을 분석하였다. 이는 수학 창의성을 여러 측면에서 고찰해봄으로써 수학 창의성 개념과 최근 연구를 이해하는데 도움을 주고자 한다.

• 한국산림과학회지
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• 제88권3호
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• pp.309-319
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• 1999

본 연구는 산림 시업에 따른 풍치 관리 정보를 파악하고자 수행하였다. 대상 임분은 현재 산림무육작업 요구도가 높은 낙엽송 인공림을 대상으로 하였다. 촬영된 임분 사진의 모의조작을 통하여 산림작업별로 구분된 35매의 임분 경관이 이용되었다. 각 경관은 신뢰성 검정을 통해 얻은 3개 집단, 전체 593명의 평가 자료를 이용하여 분석하였다. 시각 선호도 평가는 1 - 10 point 평점값을 이용하였다. 이들 평점값의 보정은 RMRATE의 SBE 분석 프로그램을 통해 실시되었다. 시각 선호도와 이미지 척도와의 관련 정도를 비교하기 위해 13매의 간벌 임분을 대상으로 어의 구별척을 이용하여 공간 이미지를 측정하였다. 일반적으로 무육 전의 자연 임분 보다는 작업 후의 쾌적하고 질서 정연한 임분을 높게 선호하고 있었다. 시각 선호도는 나지 면적과 폐잔재 면적이 증가할수록 감소하였으며 임목 밀도, 지하고, 지피식생과 높은 관련이 있었다. 소규모 개별지의 벌구 모양은 곡선보다는 직선 모양을 선호하고 있었다. 시각 선호도는 응답자의 사회경제적 변수에 따라 유의적 차이가 있었다. 연구 결과들은 산림풍치관리를 위한 시업 수행 방법을 제시하고 있다.

• 한국ITS학회 논문지
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• 제14권6호
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• pp.14-20
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• 2015

국토교통부는 2020년까지 수송부문 온실가스 배출량의 감축목표를 34.3%로 설정하였다. 목표달성을 위해 에코드라이빙 교육 및 정보를 제공하고 있으나 배출량 감축효과가 미비하다. 따라서 본 연구는 연료 효율적인 최적주행전략 모형의 개발을 목적으로 하였다. 종단경사도 및 길이가 다양한 도로지형을 생성하고 주행모드를 바탕으로 하는 시나리오별 속도 프로파일을 Comprehensive Modal Emission Model에 적용하여 연료소모량을 산정하였다. 연료소모량이 최소가 되는 시나리오와 속도변화량을 도출하였다. 도출된 시나리오와 속도변화량을 기반으로 최적주행전략 모형을 개발하였다. 개발된 모형을 검증하고자 실차테스트를 수행하여 일반 운전자의 속도 데이터를 수집하였다. 개발된 모형에 의해 생성된 속도 프로파일과 일반운전에 생성된 속도 프로파일을 분석하고 각각 연료소모량을 산정하였다. 최적주행 시 소모된 연료소모량이 일반운전보다 평균 11.8% 감축하는 것으로 분석되었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권3호
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• pp.287-299
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• 1997

Procurement, cutting, cleansing, freezing, freeze-drying, and demineralization of the allogeneic bone must be made under the germ-free stable condition without bacterial and/or viral contamination. Even thought the bone is procured under the germ free condition, we must have confidence on disinfection of all the solutions that come in contact with tissue during the whole procedure. Lots of antibacterial agents have been introduced for chemical sterilization. Recently ethylene oxide gas sterilization or radiation sterilization is frequently selected as a secendary sterilization procedure. The biological and biochemical response of the graft material differs with the type and concentration of the sterilizing agents, and various toxic reactions have been reported due to the graft material itself and the substance released by the chemicals. The authors conducted the Millipore filter test to observe the toxic effect on L929 fibroblasts according to the effect on activity of succinate dehydrogenase, during the secondary sterilization of the demineralized allogeneic bone powder with irradiation or ethylene oxide gas. The result were as follows : 1. Around the copper disk, positive control group, 10mm diameter discoloration was observed. 2. As same as the negative control group, the disk showed no discoloration. 3. The demineralized allogeneic bone which was sterilized with ethylene oxide gas or irradiation showed no cytotoxicity. 4. From this results, it is suggested that treatment with ethylene oxide gas or irradiation should be effective to sterilize the deminineralized allogeneic bone.

• 한국터널지하공간학회 논문집
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• 제16권4호
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• pp.417-430
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• 2014

도심지 내 지하공간의 효율적인 활용을 위해서 연마재 워터젯 시스템(abrasive waterjet system)을 이용한 새로운 형태의 암반굴착 공법이 개발되어 활용 중에 있다. 연마재 워터젯 시스템을 활용한 굴착(절삭) 수행 시 적정량의 연마재를 투입하고 연마재입자의 유동성을 원활하게 유지하는 것은 매우 중요하다. 본 연구에서는 실내실험을 통해 연마재 입자의 유동성과 관련된 영향인자들을 연마재 관 설치높이, 연마재 관 길이, 연마재 관 굴곡도 그리고 연마재 관 내경으로 나누어 연마재 투입량 및 유동성 수준을 평가하였다. 또한, 실험결과를 바탕으로 연마재 투입량 및 연마재 입자 유동성에 관한 최적 조건을 제시하였다. 본 연구결과를 바탕으로 향후 암반 굴착용 워터젯 공법이 도심지 내 터널, 공동구, 수직구 건설 등 다양한 지반 구조물 굴착 작업 시, 최적 연마재 투입을 위한 기초자료로 유용하게 활용될 수 있을 것으로 기대된다.

• 농업과학연구
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• 제22권1호
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• pp.11-23
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• 1995

The CAD/CAM system for the manufacturing automation is the newest technology in mechanical engineering area and becomes the important research subject nowadays. Most of all hardwares and softwares for the CAD/CAM system used in the our manufacturing companies such as automobile company are developed by the foreign country and the purchasing price of them is very expensive but their applicability to a certain area is very limited. This study was conducted to develope a CAD/CAM system for the design and the automatic manufacturing of the iron pattern shaped with 3 - dimensional free curved surface, and to test its applicability to the design and the manufacturing of the rotary blade. The results obtained from the study are as follow; 1. The CAD system which can process graphic procedures from the free curved surface shaped data was developed with personal computer. 2. The CAM main program was developed. This main program could produce CL data from CAD data file by checking the tool interference according to the cutting mode. 3. The sub. program which can simulate the tool trace from the CL data was developed. 4. The post processor for the Deckel FP2NC NC milling machine from CL data file was developed and the sub program could transmit NC program through modem to NC milling machine was developed. 5. The developed CAM system seemed to be applicable to any other system. Because the measuring results of the cross sectional thickness of the plastic model from the manufacturing iron pattern by the system showed that this system could properly check the tool interference. 6. In took 75~90 hours to manufacture two iron patterns of rotary blade. For the sake of convenience in applying to the other systems, this system was developed in BASIC and FORTRAN computer language and minimum portion of machine language as possible.

• Applied Biological Chemistry
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• 제38권6호
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• pp.496-501
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• 1995

Cellulomonas sp. KL-6 균주의 균체내 외 단백질은 배양 5일째에 $266\;{\mu}g/m{\ell},\;37\;{\mu}g/m{\ell}$로 가장 많이 생산하였다. 본 실험에서 사용한 KL-6 균주는 볏짚을 분쇄 후 1.0% NaOH와 10% $NH_4OH$로 $80^{\circ}C$에서 30분간 처리한 후 $H_3PO_4$로 중화하여 탄소원으로 이용하였을 때 각각 $1.63\;g/{\ell}$ 및 $1.47\;g/{\ell}$의 SCP가 생산되어 처리하지 않은 볏짚의 $0.5\;g/{\ell}$ 보다 균체수율이 증가되었다. KL-6 균주가 생산한 SCP의 필수아미노산의 함량이 FAO 표준단백질에 비해 많아 영양적 가치가 매우 우수하였다. 그러나 실제 동물사육에 이 균체를 이용코저 할 때는 균체의 세포벽을 파쇄후 사용해야 되리라 사료된다.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.116-122
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• 2000

On the instrumented root canal wall, amorphous, irregular smear layer can be observed with Scanning Electron Microscope(SEM). The purpose of this study was to evaluate the effect of the presence or absence of smear layer on the adhesion of Staphylococcus aureus to the dentin of the root canal. Human incisors, extracted within 7 days, with no caries, no fracture, no calcification of canal, were selected. After cutting crown portion at cemento-enamel junction, root canal preparation was done by modified crown-down technique using Profile and Gates - Glidden Drill. During canal preparation, 10ml physiologic saline solution(group1&3) or 10ml 3.5% NaOCl(group2&4) was used as irrigation solution. And 10ml physiologic saline solution(group1&3) or 10ml 0.5M EDTA(group2&4) was applicated for final flush. After vertical sectioning and ethylene oxide gas sterilization, samples(group1&2) were immersed into BHIYHM broth inoculated with Staphylococcus aureus (ATCC 31153) and incubated for 3hrs at $37^{\circ}C$. All samples were prepared for and observed with SEM(JEOL JSM840S). The data were analyzed by Mann-Whitney rank sum test. The conclusions are as follows ; 1. Smear layer covers entire root canal surface after root canal preparation. 2. Smear layer has been removed away and the entrances of dentinal tubules have opened widely, when applying 0.5M EDTA and 3.5% NaOCl. 3. A significantly higher number of bacteria were adhered to the root canal dentin without smear layer(p<0.0001). 4. Smear layer produced during root canal preparation impedes bacterial adhesion and colonization to dentin matrix, therefore inhibits canal reinfection.

• 한국산업융합학회 논문집
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• 제23권4_2호
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• pp.593-601
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• 2020

This study was conducted to analyze the physical strain with heart rate monitor in timber harvesting operations in order to reduce occupational accidents. The timber harvesting activities are manual cutting(felling, limbing and bucking) with a chainsaw and extraction by cable yarder. The study took place on Japanese larch stand. The average height was 26m and average diameter at breast height(DBH) was 3 7cm. The havest unit was gentle slope to steep slope. Results showed that the heart rate increases for chocking, felling, limbing and bucking were 94.0%, 87.9%, 84.8% and 56.4% respectively. The rate of Work Load Index was higher in the limbing(61.4%) activity than other activities chocking(55.2%), felling(54.1%) and bucking(32.1%). During 50% working heart rate test it was found that limbing(1.09), chocking(1.05) and felling(1.04) was exposed to high work intensity compared to bucking(0.83). The results showed that maximum acceptable work times(felling, chocking and limbing) were 2.30 hour, 1.85 hour and 1.60 hour respectively. To avoid occupational accidents, timber harvest workers may use a suitable working hour schedule to felling, chocking, limbing.

• 한국표면공학회지
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• 제37권5호
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• pp.249-252
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• 2004

Effects of HA and TiN coating on the electrochemical characteristics of Ti-6AI-4V alloys for bone plates were investigated using various test methods. Ti-6AI-4V alloys were fabricated by using a vacuum induction furnace and bone plates were made by laser cutting and polishing. HA was made of extracted tooth sintered and then tooth ash was used as HA coating target. The TiN and HA film coating on the surface were carried on using electron-beam physical vapor deposition (EB-PVD) method. The corrosion behaviors of the samples were examined through potentiodynamic method in 0.9% NaCI solutions at $36.5\pm$$1^{\circ}C$ and corrosion surface was observed using SEM and XPS. The surface roughness of TiN coated bone plates was lower than that of tooth ash coated plates. The structure of TiN coated layer showed the columnar structure and tooth ash coated layer showed equiaxed and anisotrophic structure. The corrosion potential of the TiN coated specimen is comparatively high. The active current density of TiN and tooth ash coated alloy showed the range of about $1.0xl0^{-5}$ $A\textrm{cm}^2$, whereas that of the non-coated alloy was$ 1.0xl0^{-4}$ $A\textrm{cm}^2$. The active current densities of HA and TiN coated bone plates were smaller than that of non-coated bone plates in 0.9% NaCl solution. The pitting potential of TiN and HA coated alloy is more drastically increased than that of the non-coated alloy. The pit number and pit size of TiN and HA coated alloy decreased in compared with those of non-coated alloy. For the coated samples, corrosion resistance increased in the order of TiN coated, tooth ash coated, and non-coated alloy.