• 대한간호학회지
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• 제30권4호
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• pp.1055-1065
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• 2000

The purpose of this study was to develop, through the integration of instructional theory, a Courseware and to investigate the effectiveness of a web-based computer assisted instruction(WBI) program for preventing drug abuse, a serious problem for youth problem. During the first stage of this study done "Drug Abuse Prevention" Courseware was developed based on, Gagn & Brigg's instructional design theory, Keller's ARCS theory and the CAI model of Hannafin & Peck. For the second stage, the courseware was used to provide education for students adolescents in drug abuse prevention. This study used an quasi-experimental, one-group pretest-posttest design with a convenience sample of 36 male high school students who were at one high school located in Seoul. Data were collected using self-reported questionnaires which included a learning achievement tool, the Keller's IMMS (Instructional Material Motivation Survey), on attitudes to drug use, and on responses to the WBI instruction. Prior to the experiment, the "drug abuse prevention" learning method and the procedures of the study were explained to the students, and then the learning achievement of the subjects was measured as a pretest. The students were then given 2 weeks WBI utilizing the courseware. A post-test which included the pre-test learning achievement questionnaire and a survey of learning motivation and attitudes toward drug were given two weeks after the education was completed. The data analysis was done using SPSS/PC. Paired t-test was used to analyze the differences between the pre-test and post-test scores for learning achievement. The results of the analysis are as follows: There were significant differences in learning achievement between the pre-test and post-test(t=-18.62, p=0.000). The hypothesis, that learning achievement will be higher, after the class has used the courseware, than before was supported. The scores for learning motivation and attitudes toward drugs were also higher than the results of existing studies. In conclusion, this study suggests that WBI is an effective learning method in the prevention of drug abuse for adolescents as it can be used for self-learning and repeated learning as assisted instruction. Recommendation would be given that further research needs to be develped in the courseware by cognitive learning style and by multimedia courseware and virtual reality system.

• 동력기계공학회지
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• 제5권2호
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• pp.22-29
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• 2001

This paper represents axial mean velocity, turbulent kinetic energy and swirl number based on momentum flux measured in the X-Y plane and Y-Z plane respectively of a cone type gas swirl burner by using X-probe from the hot-wire anemometer system. This experiment is carried out at flow rates 350 and $450{\ell}/min$ respectively, which are equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of a subsonic wind tunnel. Axial mean velocities and turbulent kinetic energies show that their maximum values exist centering around narrow slits situated radially on the edge of and in the forefront of a burner until $X/R{\fallingdotseq}1.5$, but they have a peculiar shape like a starfish diffusing and developing into inward and outward of a burner by means of the mixing between flows ejected from narrow slits, an inclination baffle plate and swirl vanes respectively according to downstream regions. Moreover, they show a relatively large value in the inner region of 0.5$S_m$ obtained by integration of velocity profiles shows a characteristic that has an inflection point composing of the maximum and minimum value until X/R<3, but shows close agreement with the geometric swirl number after a distance of X/R=3.

• 보건행정학회지
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• 제24권4호
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• pp.312-321
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• 2014

Background: To evaluate the quality of chronic care provided by public health centers located in a South Korean metropolitan city using a modified Assessment of Chronic Illness Care (ACIC). Methods: We conducted self-evaluation surveys and collected data using a modified ACIC from twenty five public health centers. Cultural validity of the original ACIC was examined by the public health and nursing science experts. Based on expert reviews, cognitive interviews, pre-test results, five items of the original ACIC that were not relevant were deleted. The response scale was changed from twelve-point Likert scale to Guttman scale but its scoring system was maintained. Results: Eighty eight percent of public health centers in this study reported that their overall quality of chronic care was at a limited or basic level. About 68% of the centers reported that the organization was as reasonably good or fully developed to provide chronic care. On the other hand, 96% of the public health centers reported that the clinical information system was at a very limited or basic support level. The decision support, the integration of Chronic Care Model components, the delivery system design, the community linkages, and the self-management support were evaluated as limited or basic level of support by more than half of the public health centers, respectively. Conclusion: In a metropolitan area of South Korea, quality of chronic care in public health centers was not found to reach acceptable levels of services. It is critical to enhance the quality of chronic care in public health centers.

• 한국정밀공학회지
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• 제27권3호
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• pp.135-141
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• 2010

Researchers continue to explore possibilities for expanding additive manufacturing (AM) technologies into direct product manufacturing. One limitation is in the materials available for use in AM that can meet the needs of end-use applications. Stereolithography (SL) is an AM technology well known for its precision and high quality surface finish capabilities. SL builds parts by selectively crosslinking or solidifying photo-curable liquid resins, and the resin industry has been continuously developing new resins with improved performance characteristics. This paper introduces a unique SL machine that can fabricate parts out of multiple SL materials. The technology is based on using multiple vats positioned on a rotating vat carousel that contain different photo-curable materials. To change the material during the process, the build platform is raised out of the current vat, a new vat with a different material is rotated under the platform, and the platform is submerged into the new vat so that the new material can be used. This paper introduces a new vat exchange mechanism, cleaning process, recoating process, resin leveling mechanism and process planning technologies for the implementation of multiple material SL. An overview of the system framework is provided and the system integration and control software is described. In addition, several multiple material test parts are designed, fabricated, and described.

• 한국멀티미디어학회논문지
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• 제9권3호
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• pp.360-368
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• 2006

최근 휴대폰의 성능이 향상되면서 다양한 부가기능을 내장한 멀티미디어 폰이 등장했다. 특히 웰빙에 대한 관심이 증가하여 바이오 기능을 휴대폰에 내장 하기위한 다양한 시도가 있어 왔다. 여러 가지 바이오 기능 중 경피 신경 전기치료기는 혈액 순환의 개선과 통증 억제의 기능이 있으므로 이를 휴대폰에 내장시키면 언제 어디서나 쉽게 전기 자극을 통해 혈액 순환을 개선하고 통증 억제를 할 수 있는 장점이 있다. 경피 신경 전기치료기를 휴대폰에 내장시키기 위해서는 소형 및 저전력의 자극모듈이 필요하며, 모듈이 오동작할 경우에도 사용자의 안전을 보장할 수 있어야 한다. 본 논문에서는 소형의 승압기를 이용하여 휴대폰에 내장가능 한 전기자극기를 설계 및 제작하였으며, 사용자의 안전을 위해 자극기의 출력단에 충전된 전체 에너지가 한꺼번에 출력되어도 인체에 무해하도록 설계하였다. 구현한 자극기 모듈의 검증을 위하여 소형의 마이크로 프로세서를 이용하여 테스트 시스템을 구현하여 성능을 검증하였다.

• 대한의용생체공학회:의공학회지
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• 제39권1호
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• pp.22-29
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• 2018

Intervertebral disc(IVD) mainly consists of Annulus fibrosus(AF) and Nucleus pulposus(NP), playing a role of distributing a mechanical load on vertebral body. IVD tissue engineering has been developed the methods to achieve anatomic morphology and restoration of biological function. The goal of present study is to identify the possibilities for creating a substitute of IVD the morphology and biological functions are the same as undamaged complete IVD. To fabricate the AF and NP combine biphasic IVD tissue, AF tissue scaffolds have been printed by 3D bio-printing system with natural biomaterials and NP tissues have been prepared by scaffold-free culture system. We evaluated whether the combined structure of 3D printed AF scaffold and scaffold-free NP tissue construct could support the architecture and cell functions as IVD tissue. 3D printed AF scaffolds were printed with 60 degree angle stripe patterned lamella structure(the inner-diameter is 5mm, outer-diameter is 10 mm and height is 3 mm). In the cytotoxicity test, the 3D printed AF scaffold showed good cell compatibility. The results of histological and immunohistochemical staining also showed the newly synthesized collagens and glycosaminoglycans, which are specific makers of AF tissue. And scaffold-free NP tissue actively synthesized glycosaminoglycans and type 2 collagen, which are the major components of NP tissue. When we combined two engineered tissues to realize the IVD, combined biphasic tissues showed a good integration between the two tissues. In conclusion, this study describes the fabrication of Engineered biphasic IVD tissue by using enable techniques of tissue engineering. This fabricated biphasic tissue would be used as a model system for the study of the native IVD tissue. In the future, it may have the potential to replace the damaged IVD in the future.

• 항공우주시스템공학회지
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• 제13권4호
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• pp.1-9
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• 2019

방송 통신, 지구관측, 기상관측, 해양관측, 그리고 항행 등 서로 다른 임무를 가지고 있는 위성들을 통합 운영하는 것은 보안에 취약하다. 현재 구성된 지상국 네트워크의 문제점은 시험 환경을 구축하여 분석하였다. 이를 바탕으로 하나의 지상국에 의해서 여려 개의 위성을 운영할 수 있는 네트워크를 설계하였다. 또한, 국내외 지상국과의 인터페이스 및 네트워크 구성방안을 제안하였다. 국내외 지상국과 연동하는 네트워크는 국가과학기술연구망과 글로벌과학기술협업연구망으로 구성하였다. 내부 네트워크는 방화벽, 가상사설망, DMZ, 1-way USB 등으로 구성하였다. 제안된 방법으로 네트워크를 구축하면 바이러스 유입 및 감염 등 유해 데이터를 차단할 수 있다.

• 한국항공우주학회지
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• 제49권12호
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• pp.971-980
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• 2021

최근 드론 기술의 대중화와 함께 저비용의 소형 무인기를 다수 또는 군집으로 운용함으로써 상당한 군사적 효용성을 얻을 수 있음이 알려지면서, 군집무인체계의 전장 활용을 위한 연구가 활발히 진행되고 있다. 국방과학연구소에서는 이와 관련한 주요기술로 군집제어, 군집통신, 군집정보, 군집협업 기술을 식별하였으며, 1단계로써 대상 무인체를 운용하는 데 필요한 군집제어와 군집통신 기술에 대한 연구를 수행하였다. 본 논문에서는 소형 고정익 무인기 기반의 군집무인기시스템을 설계 및 제작하고, 군집제어 및 군집통신 기술을 비행시험으로 검증한 과정을 소개한다. 최종비행시험에서 무인기 19대가 군집비행을 수행함으로써 국내 최초로 군사적으로 활용도가 높은 고정익 무인기 약 20대 규모의 군집 비행시험에 성공하였다.

• 지능정보연구
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• 제17권3호
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• pp.147-168
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• 2011

상품 및 서비스에 대한 개인화된 추천 서비스가 중요해짐에 따라, 많은 연구자들은 추천시스템 개발을 위한 다양한 지식과 기법들을 제공해왔다. 이러한 기법들 중에서 협업 필터링(Collaborative Fitering) 기법은 여러 분야에서 널리 사용되고 있으며, 그 유용성이 입증되었다. 하지만, 추천시스템의 성능을 더욱 높이기 위해서 현재의 협업 필터링 기법은 다음과 같은 점들을 고려해야 한다. 첫째, 대부분의 추천시스템과 관련한 연구에서 특정 고객과 성향이 유사한 다른 고객들을 찾기 위해 사용되는 유사도 함수들(Similarity Functions)은 대부분 특정한 관점에 초점을 두고 있기 때문에 다양한 관점에서 성향이 유사한 다른 고객들을 찾는데 한계를 가진다. 따라서, 특정 관점에 치우치지 않는 통합된 유사도 함수를 사용해야 할 필요가 있다. 둘째, 고객들의 성향은 시간이 지남에 따라 변화하기 때문에, 이를 추천결과에 반영하기 위해서는 시간에 따른 고객들의 구매 성향의 변화를 고려해야 한다. 본 연구는 여러 실험들을 통해 다음의 가설을 검정하는 것을 목적으로 하였다-다양한 관점이 동시에 반영된 통합 유사도 함수의 이용과 시간정보를 이용한 사용자의 구매 성향의 변화를 반영할 경우 추천의 정확도가 향상될 것이다. 다양한 실험을 통해, 본 연구에서 제시한 추천시스템은 전통적인 협업 필터링 기반의 추천시스템들에 비해 일반적으로 상당히 높은 정확도를 보였으며 이를 통해, 본 연구에서 제시한 가설이 채택될 수 있음을 확인하였다.

• 천문학논총
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• 제15권spc2호
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• pp.57-64
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• 2000

It is realized that the extraterrestrial matter is in ionized state, plasma, so the matter of this kind behaves as not expected because of its sensitiveness to electric and magnetic fields and its ability to carry electric currents. This kind of subtle change can be observed by an instrument for the magnetic field measurement, the magnetometer usually mounted on the rocket and the satellite, and based on the ground observatory. The magnetometer is a useful instrument for the spacecraft attitude control and the Earth's magnetic field measurements for the scientific purpose. In this paper, we present the preliminary design and the test results of the two onboard magnetometers of KARl's (Korea Aerospace Research Institute) sounding rocket, KSR­III, which will be launched during the period of 2001-02. The KSR-III magnetometers consist of the fluxgate magnetometer, MAG/AIM (Attitude Information Magnetometer) for acquiring the rocket flight attitude information, and of the search-coil magnetometer, MAG/SIM (Scientific Investigation Magnetometer) for the observation of the Earth's magnetic field fluctuations. With the MAG/AIM, the 3-axis attitude information can be acquired by the comparison of the resulting dc magnetic vector fields with the IGRF (International Geomagnetic Reference Field). The Earth's magnetic field fluctuations ranging from 10 to 1,000 Hz can also be observed with the MAG/SIM measurement.