• 한국산업보건학회지
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• 제1권1호
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• pp.73-81
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• 1991

To assess biological air quality, concentrations of viable airborne microbes were determined in hospital home and outdoor air from August 25 to October 18, 1990. Bacteria, fungi and thermophilic bacteria were sampled using gravitational and suctional sampling method. In bacteria groups, the Staphylococcus spp. was identified by microscopic examination and biochemical tests. Results of the study are as follows. 1. Results using the gravitational sampling method indicated that average numbers of airborne microbes in hospital home and outdoor air were 21.5, 12.2 and 17.6 CFU/plate, respectively. These levels are well within an appropriate standard of 50 CFU/plate suggested by Endo. 2. Results using the suctional sampling method indicated that total airborne microbe concentrations in hospital, home and outdoor air were 1,998, 1,363 and $1,880CFU/m^3$, respectively. All of the results were within the recommended remedial action level, $10,000CFU/m^3$ of the American Conference of Governmental Industrial Hygienists(ACGIH). 3. Concentration of thermophilic bacteria in hospital and outdoor air were 79 and $111CFU/m^3$, respectively. Thermophilic bacteria were not detected in the home air. These results were within the remedial action level, $500CFU/m^3$. 4. Concentrations of Gram negative bacilli in holpital home and outdoor air were 20.3, 23.6 and $16.8CFU/m^3$, respectively. all were within the remedial action level, $500CFU/m^3$, recommended by ACGIH. 5. Concentrations of Staphylococcus spp. in hospital, home and outdoor air were 34.8, 14.7, and $22.4CFU/m^3$. respectively. all were within the remedial action level, $75CFU/m^3$, recommended by ACGIH. The percentages of Staphylococcus spp. in total bacteria in hospital, home and outdoor air were 19.0, 10.2 and 14.5%, respectively.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.15-20
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• 2017

최근 들어 가정용 공조기가 겨울철에 히트 펌프로도 사용된다. 이 때 실외기는 저온의 외기와 열전달을 하며 관내의 냉매를 증발시킨다. 반면 여름철에 냉방기로 사용될 경우 실외기는 고온의 외기와 열전달을 통해 관 내의 냉매를 응축시킨다. 즉, 동일한 열교환기가 여름철에는 응축기로, 겨울철에는 증발기로 사용되고 외기 조건도 겨울철의 저온에서 여름철의 고온까지 넓은 범위에 놓이게 된다. 본 연구에서는 표준 설계 온도 조건에서 얻어진 j와 f 인자가 저온 운전 시에도 무리없이 적용 가능한지를 실험을 통하여 확인하였다. 이를 위하여 2열 루버 핀-관 열교환기에 대하여 외기 온도를 변화시키며 일련의 실험을 수행하였다. 또한 관 내측의 브라인의 유량이 미치는 영향도 살펴보았다. 실험 결과 외기의 온도 변화가 j와 f 인자에 미치는 영향은 무시할 만 하였다. 모든 j와 f 인자는 각각 9%, 3% 내에서 일치하였다. 따라서 표준 조건에서 얻어진 j와 f 인자를 저온 조건에 사용하여도 무리가 없다고 판단된다. 또한 관 내측 유량 변화가 j와 f 인자에 미치는 영향이 미미한 것으로 미루어 관 내측 상관식의 적용이 적절하다고 판단된다.

• Corrosion Science and Technology
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• 제8권3호
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• pp.116-118
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• 2009

Korea Institute of Construction Materials founded Seosan Outdoor Exposure Test Site 2005 at Korea, which is a part of Worldwide Exposure Network (WEN). To evaluate the test site along with other exposure test sites, three different types of paints have been under real time weathering conditions at three major weathering test facilities around the world. Using these test specimens several spectroscopic experiments along with physical tests have been performed. Also acceleration tests have been performed using the same paints. The correlation of weathered paints among three different test facilities and accelerated test results has been compared. From the results the reliability of Seosan Weathering Test Facility and reasonable life time prediction tests are discussed.

• Journal of Sport and Applied Science
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• 제8권2호
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• pp.13-18
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• 2024

Purpose: The purpose of this study is to determine the effects of a 6-week weight training and complex training program on the Y-balance test (YBT) in high school soccer players. Research design, data, and methodology: This study included 26 high school soccer players from City S. Subjects were divided into a weight training group (WTG: n=13) and a complex training group (CTG: n=13) based on their willingness to participate without medical problems. The YBT measured anterior (AT), posteromedial (PM), posterolateral (PL), and composite scores (CS), and was measured twice: before the start and after the end of training. The data were analyzed using the SPSS 25.0 statistical program to compare pre- and post-training using paired-t tests, between training groups using independent-t tests, and left-right comparisons using independent-t tests. Results: Training resulted in a significant pre- to post-training change in PL in the left foot WTG group (p<.05), with no significant change in the other measures. There were no significant differences between training groups and between left and right sides. Conclusion: To improve YBT in high school soccer players, a program to improve ankle and hip mobility and strength should be added along with improving large muscle strength through weights and comflex training.

• Computers and Concrete
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• 제18권5호
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• pp.951-968
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• 2016

In this study, pullout capacities of post-installed deformed bars anchored in low strength concrete using different bonding materials are investigated experimentally. The experimental study was conducted under outdoor and indoor conditions; on the beams of an actual reinforced concrete building and on concrete bases constructed at Istanbul Technical University (ITU). Ready-mixed cement based anchorage mortar with modified polymers (M1), ordinary cement with modified polymer admixture (M2), and epoxy based anchorage mortar with two components (E) were used as bonding material. Furthermore, test results are compared with the predictions of current analytical models. Findings of the study showed that properly designed cement based mortars can be efficiently used for anchoring deformed bars in low quality concrete. It is important to note that the cost of cement based mortar is much lower with respect to conventional epoxy based anchorage materials.

• International Journal of Concrete Structures and Materials
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• 제11권1호
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• pp.69-84
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• 2017

This paper presents results of an experimental investigation on the behaviour of bond between external glass fibre reinforced polymer reinforcement and concrete exposed to three different environmental conditions, namely, temperature cycles, wet-dry cycles and outdoor environment separately for extended durations. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Effect of the exposure conditions on the compressive strength of concrete were also investigated separately to understand the effect of changing concrete compressive strength on the pull-out strength. Based on the comparison of experimental results of exposed specimens to control specimens in terms of bond strengths, failure modes and strain profiles, the most significant degradation of pull-out strength was observed in specimens exposed to outdoor environment, whereas temperature cycles did not cause any deterioration of strength.

• 한국세라믹학회지
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• 제45권6호
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• pp.345-349
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• 2008

$TiO_2$ coating ceramic tile for self-cleaning purpose was prepared by the precipitant dropping method using $TiCl_4$ as a precursor. $TiO_2$ film was formed on the ceramic tile by spray-coating technique and heat-treated at $500^{\circ}C$ for 1 h. The size and crystalline structure of $TiO_2$ particles were 15.3 nm and anatase phase. The outdoor exposure tests were conducted and the effects of outdoor exposure test conditions, such as exhaust concentration of contamination materials (test places), the UV light intensity (irradiation direction) and coating amounts of $TiO_2$ on the self-cleaning properties were investigated by the brightness measurements. As a results, self-cleaning property of $TiO_2$ coating tile was affected by the coating amount of $TiO_2$ however, not affected by the UV light intensity included in sun's ray (irradiation direction). $TiO_2$ coating ceramic tile can be utilized for exterior finishing materials because of self-cleaning property of $TiO_2$ coating tile.

• 한국의류학회지
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• 제44권6호
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• pp.1224-1239
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• 2020

This study develops a wearable solar energy harvesting device that absorbs solar energy to generate and store power which can be used during outdoor activities by users even after dark. For this study, a prototype hat for outdoor activities at night was developed after the design of a solar energy harvesting generation, storage, and delivery system was designed that could store energy to light up LEDs. First, the main control board of the system was designed to integrate the charging function, the darkness detection circuit, the battery voltage sensing circuit, and the LED driving circuit in order to reduce bulkiness and minimize the connection structure. It was designed to increase convenience. Second, the system was designed as a wearable fashion product that connected each part with fiber bands and manufacturing it so as to be detachable from the hat. Third, charging and LED operation tests show that the battery is fully charged after 5 hours even in winter when the illuminance value is low. In addition, the LED operation experiment verified the effectiveness of a buffered system that could operate the LEDs for about 3 hours at night.

• 보존과학회지
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• 제36권6호
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• pp.549-561
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• 2020

석간주, 진사, 황토, 자황, 웅황, 석록, 뇌록, 석청 및 백토 등 천연 무기안료 9종의 성능과 수명을 평가하고자 실내 촉진내후성과 옥외폭로 시험을 수행하였다. 실내 촉진내후성 시험법은 국내 기후 특성 및 단청의 위치 환경을 반영하여 설계하였고 필드 재현성을 확인하기 위해 서울 숭례문과 대전 연구소 등 2개소에서 옥외폭로 시험을 병행하였다. 또한 누적 자외선량을 기준으로 안료 표면의 물리적 특성 변화를 모니터링하였다. 이 결과, 석간주와 백토는 초기에 미세균열이 발생하지만 안정화된 반면 진사와 석록은 균열이 지속적으로 확대되었다. 황토와 뇌록은 수분 및 송진에 의한 얼룩이 두드러졌고 자황, 웅황 및 석청은 입자의 광택 저하가 나타났다. 각 시험별 안료의 색 변화는 절대적인 수치 차이가 있을 뿐 색도 변화 양상은 유사하였다. 백토와 뇌록의 색차(𝚫E) 값이 5 이하로 가장 작고 진사는 28 이상으로 컸다. 안료 표면의 물리적 변화는 실내 촉진내후성 시험보다는 옥외폭로 시험이, 옥외폭로 시험에서는 대전 연구소보다 서울 숭례문에서 가중되었다. 이는 옥외폭로 시험이 큰 폭의 온·습도 변화, 분진 침적에 따른 오염 등 다양한 환경에 노출되고, 특히 서울 숭례문은 총 누적 자외선량(334 MJ/m²)에 도달하는 데까지 오랜 시간이 소요되어 노출 기간이 장기화되었기 때문이다.

• 대한기계학회논문집B
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• 제37권7호
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• pp.621-627
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• 2013

2011년 7월과 8월에 걸쳐 하이브리드 제습냉방기의 실증 실험를 진행하였다. 계측 자료들은 인터넷 회선을 통해 원격 모니터링을 하며 및 취득하였다. 취득한 자료를 바탕으로 하여 하이브리드 제습냉방시스템의 실거주 환경에서 외기조건에 따른 성능을 분석하였다. 또한 실증실험에서 나타난 외기 조건에 대해 성능 시뮬레이션을 수행하여 실험값과 비교하였다. 실험과 시뮬레이션 결과는 대체로 일치하였다. 외기습도가 높은 경우 예측결과와 같이 실증 실험에서도 시스템 성능이 감소하는 것이 확인되었다.