• 지역사회간호학회지
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• 제12권1호
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• pp.142-149
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• 2001

The health education for elementary school students is a very important factor in the development of adult health practices. Particularly, eyesight is difficult to recover if lost. Therefore, prevention is better than cure. This study was conducted to investigate the factors that affect the visual health behavior of elementary school students and to furnish basic materials and directions for the promotion of elementary school health. The investigation was carried out for 4 days from 9. 18. 2000 to 9. 21. 2000 for 199 children in 3 elementary schools. A questionnaire was composed of 3 questions about general property. 20 questions about visual health behavior. 7 questions about visual self-efficacy. 5 questions about visual motivation. 16 questions about self-conception. 20 questions about the health locus of control. The data was analysed by an SAS program for t-test. ANOVA. correlation, and multiple regression tests. The results are as follows. 1. The visual health behavior of elementary school children was good (average 52.53). 2. For visual health behavior, school, year, and sex were influential factors. economic levels were not. 3. Visual health behavior had a significant correlation with visual self-efficacy, visual health motives and self-conception. but not with the locus of control. 4. In the multiple regression test, visual self-efficacy and self-conception were significant prediction factors -- the suitability of the regression model was 30.8%. Suggestions from the results are as follows: First, school year and sex had a significant influence on visual health behavior: therefore, it is necessary to consider these two factors when education programs are developed. Second, this study was carried out for students in a partial area only. Therefore, repeated studies for a large sample are necessary for the future.

• 생물환경조절학회지
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• 제9권2호
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• pp.107-114
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• 2000

우리나라의 주요지역에 대하여 일최저기온의 월평균값, 일최고기온의 월평균값, 전천일사량의 월평균값을 사용하여 외기온과 전천일사랑과의 관계를 도시하고, 온실의 형태와 작물의 종류에 따른 한계 최저외기온 및 한계 최고외기온을 산정하여 Climagraph를 작성하였다. 이 그래프를 이용하면 지역별로 냉난방설비를 이용하지 않고 온실재배가 가능한 기간을 결정할 수 있을 뿐만 아니라 각종의 온실재배작물을 재배하기에 적절한 지역을 선정하는데 이용될 수 있고, 지역별 기후특성 분석, 지역별 온실특성의 규명, 작물의 생육환경 추정 및 조절, 온실작물생산의 합리적인 계획등을 위한 도구로도 이용될 수 있을 것이다. 본 연구를 수해하면서 climagraph를 작성하는데 필요한 명확한 자료를 구하기가 상당히 어려웠기 때문에 이러한 그래프를 국내의 온실재배에 효율적으로 이용하기 위해서는 많은 추가적인 연구가 필요할 것으로 판단되었다. 특히 난방과 냉방기간을 결정함에 있어 경계시기를 결정하는데 필요한 구체적인 자료를 구하기가 어려웠으며, 작물별 생육에 필요한 한계 최저회부일사랑을 결정 하는데 어려움이 있었다.

• 한국지리정보학회지
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• 제12권3호
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• pp.143-151
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• 2009

임상도는 산림자원이 어디에 어떻게 얼마나 분포하고 있는가를 보여주는 대표적인 산림지도로 전국 산림에 대해 임상, 영급, 경급, 소밀도 등 다양한 산림정보를 제공하여 산림정책 수립의 주요한 자료로 활용될 뿐만 아니라 토지적성평가, 생태자연도 제작 등 다양한 분야의 기초 자료로 활용되고 있다. 최초의 수치임상도는 1차 NGIS 사업을 통해 제작되었는데 당시 수치임상도제작 표준의 부재로 도엽 간 경계 및 속성 불일치 등 여러 가지 유형의 오류가 발생하였다. 또한 임상도의 제작시기, 항공사진 촬영시기, 속성 설명 등 임상도에 관한 보다 자세한 정보를 알기 어려웠다. 이러한 문제점을 해결하기 위해 본 연구에서는 수치임상도 DB 설계부터 수치화, 메타데이터 입력, 품질관리 등의 수치임상도 전 제작과정을 3단계 33개 단위 공정으로 구조화하고 이를 최적화하여 표준화한 수치임상도 표준제작체계를 개발하였다. 본 수치임상도 표준제작체계를 토대로 전국 수치임상도를 일관된 품질로 제작하고 수치임상도에 대한 보다 상세한 정보를 표준메타데이터를 통해 제공할 수 있게 되었다.

• 한국항공우주학회지
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• 제48권12호
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• pp.997-1004
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• 2020

Synchropter는 서로 경사진 한 쌍의 회전날개가 동조 교차 회전하는 회전익 항공기의 일종으로 동축반전 헬리콥터와 마찬가지로 꼬리 회전날개를 제거할 수 있어서 효율적이며 간결한 형태의 비행체 구성이 가능하다. 드론 체계로서의 적합성을 검토하기 위하여 소형 Synchropter를 설계, 제작하여 비행시험을 수행하였다. 설계한 Synchropter는 로터 직경이 1.4m이며 중량이 7kg인 소형비행체로서 효율적으로 비행 특성을 확인하기 위하여 상용부품 기반으로 제작하였다. 비행 제어 시스템은 Open Architecture인 Pixhawk를 기반으로 구성하였으며, Sychropter 제어법칙을 PX4 펌웨어에 탑재할 수 있도록 개발하였다. 정성적 비행시험을 통해 Synchropter의 비행 특성을 분석하였으며, 분석 결과, 드론 체계로서의 활용 가능성을 파악할 수 있었다.

• 디지털산업정보학회논문지
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• 제19권2호
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• pp.135-145
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• 2023

ChatGPT is an artificial intelligence-based conversation agent developed by OpenAI using natural language processing technology. In this study, an empirical study was conducted on incumbent teachers on the intention to use the newly emerged Chat GPT. First, we studied how accuracy, entertainment, system accessibility, perceived usefulness, and perceived ease of use affect ChatGPT's acceptance intention. In addition, we analyzed whether perceived usefulness and perceived ease of use differ in the intention to accept depending on the digital technology of teachers. As a result of the study, the suitability of the structural equation model was generally good. Accuracy and entertainment were found to have a significant effect on perceived usefulness, and system accessibility was found to have a significant effect on perceived ease of use. In the analysis of teachers' digital technology control effects, it was found that perceived usefulness and perceived ease of use had a control effect between acceptance intentions. It was found that the group with high digital skills of teachers was strongly intended to accept the service regardless of perceived usefulness and ease of use. In the group with low digital skills of teachers, it is thought that ChatGPT's service shows the acceptance intention only when the perceived usefulness and ease of use are high. Therefore, in the group with low digital technology, it is necessary to seek teaching activities such as the development of instructional models using ChatGPT.

• 한국지리정보학회지
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• 제26권4호
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• pp.188-199
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• 2023

국내외 대표적인 범죄예방수단으로 CCTV가 활용되고 있지만, CCTV의 범죄예방효과에 관한 검증은 부족한 상황이다. 이에 본 연구에서는 도시공간 내에서 CCTV가 방범에 유효한 위치에 설치되었는지, 범죄예방효과를 나타내고 있는지 S시를 사례로 분석해 보았다. 먼저 CCTV 위치 적절성 분석결과, 범죄발생이 없는 곳에 CCTV가 설치된 경우가 많은 것으로 나타났다. 또한 주거·상업지역 등을 포함한 275개 케이스를 구성하여 CCTV의 범죄예방효과를 검증하였다. WDQ 지수를 적용하여 CCTV 감시면적과 주변지역에 미친 영향을 종합적으로 분석하여, 최종적인 범죄예방효과를 판단하였다. 분석결과 사례지역의 CCTV 설치는 주변지역에 범죄통제이익 '확산효과'가 나타난 케이스가 53.09%로, 전이효과가 나타난 경우보다 4배 가량 많게 나타났다. CCTV 설치로 인해 범죄발생이 다른 장소로 전이되는 것보다, 도시공간적으로 범죄예방효과가 확산된 것이다. 범죄예방효과를 확대하기 위해 CCTV 설치를 위한 가이드라인 마련이 요구되며, 실시간으로 축적되는 빅데이터를 적극적으로 활용하고, 범죄정보의 DB화, 분석을 통해 방범장비 설치 및 운영체계가 마련되어야 할 것이다.

• 한국응용과학기술학회지
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• 제41권2호
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• pp.172-187
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• 2024

비임상시험관리기준에서 독성시험 전 분석법 밸리데이션은 농도 설정 및 시료 제조 측면에서 중요하다. 시험기관에서는 의뢰받은 시험물질 2종에 대한 밸리데이션을 고성능액체크로마토그래피를 이용하여 수행한 결과 특이성, 시스템 적합성, 직선성, 일내 재현성, 균질성, 안정성, 농도분석, 품질관리를 판정 기준에 만족하는 분석방법을 확립 및 검증하였다. 하지만 의뢰기관의 시험성적서상 표준물질 함량은 시험기관의 결과보다 1.34배, 1.17배 높은 결과로 나타나 비임상시험관리기준에 적합한 분석법 밸리데이션을 통한 결과 도출이 신뢰성과 안정성 확보 측면에서 중요함을 확인하였다.

• Journal of Chest Surgery
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• 제17권1호
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• pp.157-166
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• 1984

These biologic test procedures are designed to test the suitability of P.V.C. made in Korea intended for parenteral preparation, which were based on the U.S. Pharmacopeia XIX "Biologic Test-Plastic Container", Official from July 1, 1975. Healthy adult human blood and rabbits weighing 2\ulcorner.2Kg were used for test materials. Sample P.V.C. were sampled from the medical equipments made in Korea randomly and Control P.V.C. were sampled from the standardized Cobe and Polystan P.V.C. tubes. P.V.C. extract was prepared from a homogeneous P.V.C. samples by incubating 60 square centimeters of the sample per 20 millimeters of sterile pyrogen-free saline at 70\ulcorner for 72 hours or autoclaving at 120\ulcorner for 1 hour. The Implantation Test was designed to evaluate the reaction of living tissue to the plastic by the method of the implantation of the Sample itself into animal tissue. The Systemic Injection Test, the Intracutaneous Test, and the remainders were designed to determine the biological response of animals to plastics by the single-dose injection of specific extracts prepared from a Sample. The results are as follows; 1.Implantation Test - No significant difference for reactions was noted between the Sample treated animal and the Control after 72 hours of implantation. 2.Systemic Toxicity Injection Test - No sign of toxicity and/or death immediately after injection and at 4, 24, 48 hours respectfully after injection. 3.Intracutaneous Test - None of the animals treated with the Sample showed a significantly greater reaction than the observed in the animals treated with Blank. 4.Pyrogen Assay-Only one animal treated with the Sample showed the maximal rise of rectal temperature about 0.2\ulcorner after 3 hours of injection, but remainders showed no change. 5.Hemolytic Index - The positive Control tube of distilled water exhibited complete hemolysis while the negative Control tube and P.V.C. extract were negative demonstrating no hemolysis. 6.Cell Morphology of Erythrocytes and Leukocytes on Stored, Heparinized Human Blood -- There was no significant difference in the morphology of either the Control or Sample extract. 7.Clotting Mechanism of Human Blood in vitro - After allowing to the P.V.C. extract at room temperature for 5 Hours and at 10\ulcorner for 24 hours, there was no appreciable difference in Prothrombin Time under these conditions. 8.Clotting Mechanism of Rabbit in vivo - At the termination of 5 days after intraperitoneal injection of the P.V.C. extract, no significant changes in Clotting Time were observed. According to the above results, it could be concluded that the P.V.C. made in Korea was acceptable for parenteral preparation, especially treated with physiologic saline and/or human blood.man blood.

• 전기학회논문지
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• 제67권5호
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• pp.635-643
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• 2018

This paper propose a method to identify the motor parameters and improve input voltage error which affect the low speed position error of the back-emf(back electromotive force) based sensorless algorithm and to secure the operation reliability and stability even in the case where the load fluctuation is severe and the start and low speed operation frequently occurs. In the model-based observer used in this paper, stator resistance, inductance, and input voltage are particularly influential factors on low speed performance. Stator resistance can cause resistance value fluctuation which may occur in mass production process, and fluctuation of resistance value due to heat generated during operation. The inductance is influenced by the fluctuation due to the manufacturing dispersion and at a low speed where the change of the current is severe. In order to find stator resistance and inductance which have different initial values and fluctuate during operation and have a large influence on sensorless performance at low speed, they are commonly measured through 2-point calculation method by 2-step align current injection. The effect of voltage error is minimized by offsetting the voltage error. In addition, when the command voltage is used, it is difficult to estimate the back-emf due to the relatively large distortion voltage due to the dead time and the voltage drop of the power device. In this paper, we propose a simple circuit and method to detect the voltage by measuring the PWM(Pulse Width Modulation) pulse width and compensate the voltage drop of the power device with the table, thereby minimizing the position error due to the exact estimation of the back-emf at low speed. The suitability of the proposed algorithm is verified through experiment.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.15-15
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• 2011

As you know, boron compounds, borax ($Na_2B_4O_5(OH)_4{\cdot}8H_2O$) etc. were known thousands of years ago. As for natural boron, it has two naturally occurring and stable isotopes, boron 11 ($^{11}B$) and boron 10 ($^{10}B$). The neutron absorption $^{10}B$ is included about 19~20% with 80~81% $^{11}B$. Boron is similar to carbon in its capability to form stable covalently bonded molecular networks. The mass difference results in a wide range of ${\beta}$ values between the $^{11}B$ and $^{10}B$. The $^{10}B$ isotope, stable with 5 neutrons is excellent at capturing thermal neutrons. For example, it is possible to decrease a thermal neutron required for the nuclear reaction of uranium 235 ($^{235}U$). If $^{10}B$ absorbs a neutron ($^1n$), it will change to $^7Li+^1{\alpha}$ (${\alpha}$ ray, like $^4He$) with prompt ${\gamma}$ ray from $^{11}B$ $^{11}B$ (equation 1). $$^{10}B+^1n\;{\rightarrow}\;^{11}B\;{\rightarrow}\; prompt \;{\gamma}\;ray (478 keV), \;^7Li+4{\alpha}\;(4He)\;\;\;\;{\cdots}\; (1)$$ If about 1% boron is added to stainless steel, it is known that a neutron shielding effect will be 3 times the boron free steel. Enriched boron or $^{10}B$ is used in both radiation shielding and in boron neutron capture therapy. Then, $^{10}B$ is used for reactivity control and in emergency shutdown systems in nuclear reactors. Furthermore, boron carbide, $B_4C$, is used as the charge of a nuclear fission reaction control rod material and neutron cover material for nuclear reactors. The $B_4C$ powder of natural B composition is used as a charge of a control material of a boiling water reactor (BWR) which occupies commercial power reactors in nuclear power generation. The $B_4C$ sintered body which adjusted $^{10}B$ concentration is used as a charge of a control material of the fast breeder reactor (FBR) currently developed aiming at establishment of a nuclear fuel cycle. In this study for new boron compound, silicon boride ceramics for capturing thermal neutrons, preparation and characterization of both silicon tetraboride ($SiB_4$) and silicon hexaboride ($SiB_6$) and ceramics produced by sintering were investigated in order to determine the suitability of this material for nuclear power generation. The relative density increased with increasing sintering temperature. With a sintering temperature of 1,923 K, a sintered body having a relative density of more than 99% was obtained. The Vickers hardness increased with increasing sintering temperature. The best result was a Vickers hardness of 28 GPa for the $SiB_6$ sintered at 1,923K for 1 h. The high temperature Vickers hardness of the $SiB_6$ sintered body changed from 28 to 12 GPa in the temperature range of room temperature to 1,273 K. The thermal conductivity of the SiB6 sintered body changed from 9.1 to 2.4 W/mK in the range of room temperature to 1,273 K.