• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.499-503
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• 2005

본 논문은 Wireless LAN을 이용함에 있어서 사용공간에 따른 이용 범위를 측정하고, 이를 참고하여 실사용 환경에서 Wireless LAN 환경을 구축하기 위한 참고, 자료로서 활용가능토록 측정되었다. 구성환경은 Wireless LAN의 미국 표준인 IEEE 802.11b 시스템을 기반으로 한 Wireless LAN을 대상으로 구성했으며, 캠퍼스 환경에의 적용이라는 전제를 가지고 실제 측정을 통하여 작성했다. 측정은 실사용 환경인 Office Environment와 Open Space 환경에서 이용 가능거리의 측정과 각 거리에 따른 신호의 S/N 비를 측정하여 학내 Wireless LAN 망 환경구현에 기초가 되는 데이터로서 측정했다. 단, 실내 환경에서의 측정은 기본 차폐물로서 벽이 2개 이상 존재할 경우를 대상으로 하였으며, 실외 환경에서의 측정은 차폐물이 없을 경우, 1차적인 차폐물이 존재할 경우, 그리고 2차적인 추가 차폐물이 존재할 경우를 나누어서 수행했다.

• 인간식물환경학회지
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• 제24권6호
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• pp.585-593
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• 2021

Background and objective: Illegal open-air incineration, which is criticized as a leading source of air pollutants among agricultural activities, currently requires constant effort and attention. Countries around the world have been undertaking studies on the emission of heavy metal substances in fine dust discharged during the incineration process. A precise analytical method is required to examine the harmful effects of particulate pollutants on the human body. Methods: In order to simulate open-air incineration, the infrastructure needed for incineration tests complying with the United States Environmental Protection Agency (EPA) Method 5G was built, and a large-area analysis was conducted on particulate pollutants through automated scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS). For the test specimen, high-density polyethylene (HDPE) waste collected by the DangJin Office located in Choongcheongnam-do was used. To increase the identifiability of the analyzed particles, the incineration experiment was conducted in an incinerator three times after dividing the film waste into 200 g specimens. Results: Among the metal particulate matters detected in the HDPE waste incineration test, transition metals included C (20.8-37.1 wt%) and O (33.7-37.9 wt%). As for other chemical matters, the analysis showed that metal particulate matters such as metalloids, alkali metals, alkaline earth metals, and transition metals reacted to C and C-O. Si, a representative metalloid, was detected at 14.8-20.8 wt%, showing the highest weight ratio except for C and O. Conclusion: In this study, the detection of metal chemicals in incinerated particulate matters was effectively confirmed through SEM-EDS. The results of this study verified that HDPE waste adsorbs metal chemicals originating from soil due to its own properties and deterioration, and that when incinerated, it emits particulate matters containing transition metals and other metals that contribute to the excessive production and reduction of reactive oxygen species.

• Human Ecology Research
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• 제61권4호
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• pp.543-563
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• 2023

The purpose of this study is to design and develop a Metaverse ZEP platform-based teaching and learning process plan by selecting learning topics that are commonly dealt with among the core concepts of the "family" area of practical (technical and home) subjects. To this end, a teaching and learning process plan was developed through planning, Metaverse platform design, expert review, and revision stages. The Metaverse ZEP "Open Class Day" platform, a virtual learning space, was created and developed to further utilize EduTech programs, such as Padlet, Mentimeter, Jamboard, Miricanvas, and Spatial. The teaching and learning process plan developed in this study consists of a total of seven sessions, including approaching EduTech, Changing Families, Exploring Our Family, and Counseling Centers 1, 2, and 3. Among them, Geumji Counseling Center 1, 2, and 3 was designed as a class in which parents and children participate together in open classes using the ZEP platform. This platform can be used as part of parent classes as well as to encourage online participation in the open classes held periodically at each individual school. In terms of the content validity ratio (CVR) of the developed teaching and learning process verified through five experts, 12 out of 15 questions had a CVR of 1, while the remaining three questions had a CVR of 0.6. The three questions with lower validity were revised and supplemented.

• 대한인간공학회지
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• 제6권1호
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• pp.41-44
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• 1987

Researches were made on foot-warming, anti-bacteria and deodorant treatment. Feet, the very important organ to human body, perspire much and their temperature is lower than those of other parts. Hence, keeping feet warm, sanitary and deodorant is the area of this study. Latex sponge of activated carbon, impregnated open cell foam, treated with Vikol DZ-anti-bacteria finishing agent, was developed and tested for warmth-keeping by KSK 0560 test method and for sanitization by AATCC 90 HALO test method and for deodorization by wearing tests. The results show that the new developed latex spongee has warmth-keeping ratio of 2.5 times higher than that of the conventional spong and it has an excellent anti-bacteria effect. Actual wearing function tests also show that it improves significantly the performance of deodorization, sanitization, warmth-keeping and bulkiness.

• 교육시설
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• 제5권3호
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• pp.91-97
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• 1998

The purpose of this study is to investigate elementary school landscaping. The landscaping has intrinsic value for educational purpose as well as an open space resource in urban area. Four elementary schools in Taegu were surveyed and analyzed to identify the ratio of greenery, green volume and its maintenance. The result can be summarized as follows: 1. While 58 species of trees were quoted all over the text book, 17 to 52 species were found in each school and only few species were always dominant in each school. 2. The greenery and green volume were insufficient in terms of quantity and inadequate in placement, and there were differences in landscaping quality and quantity between schools. However the differences were not associated with the age of schools. 3. Functional implementations of landscaping technique(for example, environmental control) were needed for future landscaping of elementary schools.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.542-547
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• 2004

The objective of this study is 0 estimate wind pressure acting on soundproof tunnel and noise reduction through the tunnel. For the purpose various shape of scale models were prepared and drag forces acting on each models were measured in wind tunnel. And numerical simulation was performed to confirm experimental results. As a result the lowest drag force coefficient of 0.59 was obtained in the case of arch roof shape model. Noise reduction through soundproof tunnel was simulated by using ray tracing method according to various open ratio of its roof area.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.406-409
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• 2005

In the forging operation of large ingot two break-down process are upsetting and cogging. The first purpose of upsetting is to ensure sufficient forging ratio for subsequent cogging operations and consolidate the voids along the centerline. The second purpose is related to improve the physical properties for a final product. Voids which are generated during the casting process can be one of the decisive defects of materials. So it is necessary to know the standard of Judgment for void-closure in upsetting operation. In practical conditions, FEM analysis(DEFORM 2D 8.1) was carried out to decide how much effective strain has influence on void-closure. It is finally suggested that the function consists of the effective strain of analysis data and the area rate of void.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.2964-2983
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• 2015

As the Android operating system has become a key target for malware authors, Android protection has become a thriving research area. Beside the proved importance of system permissions for malware analysis, there is a lot of overlapping in permissions between malware apps and goodware apps. The exploitation of them effectively in malware detection is still an open issue. In this paper, to investigate the feasibility of neuro-fuzzy techniques to Android protection based on system permissions, we introduce a self-adaptive neuro-fuzzy inference system to classify the Android apps into malware and goodware. According to the framework introduced, the most significant permissions that characterize optimally malware apps are identified using Information Gain Ratio method and encapsulated into patterns of features. The patterns of features data is used to train and test the system using stratified cross-validation methodologies. The experiments conducted conclude that the proposed classifier can be effective in Android protection. The results also underline that the neuro-fuzzy techniques are feasible to employ in the field.

• 대한기계학회논문집
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• 제14권5호
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• pp.1087-1095
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• 1990

본 연구에서는 슬롯을 가지는 2차원 원형 풍동에 대하여 슬롯의 갯수, 크기와 흐름의 속동에 따른 공진 특성을 2차원 8-노드 등계수(isoparametric)요소를 사용하여 해석한다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.225-229
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• 2012

대기가 희박한 고고도 환령이나 급격한 선회를 위해 2차분사에 의한 추력벡터제어를 사용한다. 8개의 2차분사구를 갖는 고체로켓모터를 대상으로, 2차분사의 유량을 조절하는 밸브의 개도가 추력, 측추력 및 롤 모멘트에 미치는 영향을 해석적으로 연구하였다. 정상 상태의 3차원 Reynolds Averaged Navier-Stokes 식의 해를 구하였으며, 난류를 위해 Spalart-Almaras 모델을 사용하였다. 수치해석의 타당성을 평가하기 위해 실험 결과와 해석결과를 비교하였다. 밸브의 개도가 증가함에 따라 추력은 감소하나 측추력은 증가한다. 반면, 롤 모멘트의 경우, 밸브와 2차분사 파이프의 상호작용에 의해 개도에 비례하지 않는다.