• Steel and Composite Structures
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• 제18권4호
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• pp.925-946
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• 2015

This paper presents a new cost-effective hybrid GFRP-Concrete deck system that the GFRP panel serves as both tensile reinforcement and stay-in-place form. In order to understand the fatigue behavior of such hybrid deck, fatigue test on a full-scale specimen under sagging moment was conducted, and a series of static tests were also carried out after certain repeated loading cycles. The fatigue test results indicated that such hybrid deck has a good fatigue performance even after 3.1 million repeated loading cycles. A three-dimensional finite element model of the hybrid deck was established based on experimental work. The results from finite element analyses are in good agreement with those from the tests. In addition, flexural fatigue analysis considering the reduction in flexural stiffness and modulus under cyclic loading was carried out. The predicted flexural strength agreed well with the analytical strength from finite element simulation, and the calculated fatigue failure cycle was consistent with the result based on related S-N curve and finite element analyses. However, the flexural fatigue analytical results tended to be conservative compared to the tested results in safety side. The presented overall investigation may provide reference for the design and construction of such hybrid deck system.

• 말소리와 음성과학
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• 제8권4호
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• pp.49-61
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• 2016

The present study investigates the perception of Korean phonation types by native speakers of Aymara. Perception tests were conducted on two sets of Korean speech materials to determine correspondence between Korean and Aymara 3-way contrasts and to find out which of the consonantal and vocalic part of the syllable is more influential in the perception of Korean phonation types. A set of manipulated stimuli, as well as a set of 12 spontaneous words, were prepared for the tests. The first syllable of the 12 Korean bisyllabic words of 3 series of phonation types(Lenis, Aspirated, and Fortis) in 4 places of articulation were split into consonantal and vocalic parts. And then the two parts were combined to form 9 tokens of CV sequences respectively for each place of articulation. Native speakers of Aymara were forced to match Korean stimuli with one of the 15 Aymara words which represent 3 series of consonant types(plain, aspirated, and ejective) in 5 places of articulation(bilabial, alveolar, palatal, velar, and uvular). Results showed that the consonantal part is more influential than the vocalic part to the Aymara subjects' perception of Korean phonation types when the consonantal part is Aspirated in its phonation type, but the vocalic part is more influential than the consonantal part when the consonantal part is Lenis or Fortis in its phonation type. Response analysis showed that Aymara subjects tend to match Korean stops to Aymara ones in such a way that Lenis corresponds to aspirated, Aspirated to aspirated, and Fortis to plain.

• 한국임상수의학회지
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• 제28권6호
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• pp.566-570
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• 2011

본 연구에서는 난소자궁적출술에 있어서 티타늄(titanium) 클립 적용 시 발생할 수 있는 합병증을 평가하고, 난소혈관과 난소걸이인대의 두 가지 결찰법을 비교하여 합병증을 최소화 할 수 있는 수술법을 찾고자 하였다. 실험을 위해 6마리의 암컷 비글견이 사용되었으며, 세 마리씩 두 그룹으로 나누어 한 그룹은 난소걸이인대와 난소혈관을 함께 결찰 하였고, 나머지 한 그룹은 난소걸이인대를 결찰하지 않고 난소혈관만 결찰 하였다. 두 수술법을 비교하기 위해서 매달 1회씩 1년 동안 복강 X-ray 검사를 통해 적용된 클립의 위치 변화를 확인하였고, 적용된 클립에 의한 염증반응 유무는 혈액검사를 통해 확인하였다. X-ray 검사 상에서 두 그룹의 클립 위치는 큰 변화를 보이지 않았으며, 혈액 검사에서도 거의 모든 수치들이 정상범위에 있었고, 염증과 관련된 임상증상 또한 관찰되지 않았다. 부검을 통한 두 그룹의 클립 포매 형태를 관찰한 결과 난소걸이인대를 결찰한 클립은 복강의 얇은 막으로 두껍게 싸여서 신장 후연에 위치하고 있는 것을 확인하였고, 난소걸이인대를 결찰하지 않은 클립은 얇게 둘러싸인 막 표면에 위치하여 신장의 아래쪽에서 관찰되었다. 이러한 결과는 난소걸이인대가 클립의 움직임을 최소화 할 수 있도록 지지해주는 역할을 하는 것을 의미하며, 따라서 티타늄 클립을 적용하는 난소자궁적출술에서 난소걸이인대를 함께 결찰하는 방법이 합병증 예방에 있어서 보다 적합한 방법으로 생각된다.

• Nutrition Research and Practice
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• 제4권4호
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• pp.332-338
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• 2010

The purpose of this study was to examine consumers' behaviors toward ready-to-eat foods and to develop ready-to-eat food market segmentation in Korea. The food-related lifestyle and purchase behaviors of ready-to-eat foods were evaluated using 410 ready-to-eat food consumers in the Republic of Korea. Four factors were extracted by exploratory factor analysis (health-orientation, taste-orientation, convenience-orientation, and tradition-orientation) to explain the ready-to eat food consumers' food-related lifestyles. The results of cluster analysis indicated that "tradition seekers" and "convenience seekers" should be regarded as the target segments. Chi-square tests and t-tests of the subdivided groups showed there were significant differences across marital status, education level, family type, eating-out expenditure, place of purchase, and reason for purchase. In conclusion, the tradition seekers consumed more ready-to-eat foods from discount marts or specialty stores and ate them between meals more often than the convenience seekers. In contrast, the convenience seekers purchased more ready-to-eat foods at convenience stores and ate them as meals more often than the tradition seekers. These findings suggest that ready-to-eat food market segmentation based on food-related lifestyles can be applied to develop proper marketing strategies.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.268-271
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• 2008

If a reactor vessel is failed to retain a molten corium in a postulated severe accident, the molten corium is released outside the reactor vessel into a reactor cavity. The molten corium would attack the concrete wall and basemat of the reactor cavity, which may lead to inevitable concrete decompositions and possible radiological releases. In the OECD/MCCI project, a series of tests were performed to secure the data for cooling the molten corium spread out at the reactor cavity and for the long-term CCI (Core Concrete Interaction). Also, a MCCI (Molten Core Concrete Interaction) analysis code, CORQUENCH was upgraded at Argonne National Laboratory with embedding the new models developed for the tests. This paper deals with analyses of MCCI at plant scale under the conditions of top flooding using the upgraded CORQUENCH code. The modeling approach is briefly summarized first, followed by presentation of a validation calculation that illustrates the predicative capability of the modeling tool. With this background in place, the model is then used to carry out a parametric set of scoping calculations that define approximate coolability envelopes for the LCS (Limestone Common Sand) concrete that has been evaluated in the OECD/MCCI project.

• 드라이브 ㆍ 컨트롤
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• 제21권1호
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• pp.16-21
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• 2024

The yaw gearbox is a key device in a wind power generator that improves power generation efficiency by rotating hundreds of tons (400 to 600 tons) of nacelle so that the blade reaches 90 degrees in the wind direction. Recently, installation sites have been advancing from land to sea as they have become super-large at (8-12) MW to increase the economic feasibility of wind power generators and utilize excellent wind resources, and the target life of large wind power generators is 25 to 30 years. The yaw gearbox of 6 to 12 sets is installed in a very complex place inside the nacelle on the tower with parallels, and it is important to secure the reliability of the yaw gearbox because if a failure occurs after installation, it costs tens to hundreds of times the price of a new product to restore. In this study, equivalent loads were calculated by analyzing failure mode and field data, accelerated life test conditions were established, and a test device was constructed to perform the accelerated life tests and performance tests to ensure the reliability of the gearbox.

• Asian Pacific Journal of Cancer Prevention
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• 제14권9호
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• pp.5023-5029
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• 2013

Background: To evaluate knowledge about screening tests and tests without proven screening value in a Greek Breast Unit population undergoing benign vacuum-assisted breast biopsy (VABB). Materials and Methods: This study included 81 patients. Three knowledge-oriented items (recommended or not, screening frequency, age of onset) were assessed. Regarding screening tests two levels of knowledge were evaluated: i). crude knowledge (CK), i.e. knowledge that the test is recommended and ii). advanced knowledge (AK), i.e. correct response to all three knowledge-oriented items. Solely CK was evaluated for tests without proven screening value. Risk factors for lack of knowledge were assessed with multivariate logistic regression. A second questionnaire was administered 18 months after VABB to assess its impact on the performance of tests. Results: Concerning screening tests considerable lack of AK was noted (mammogram, 60.5%; Pap smear, 59.3%; fecal occult blood testing, 93.8%; sigmoidoscopy, 95.1%). Similarly lack of CK was documented regarding tests without proven screening value (breast self-examination, 92.6%; breast MRI, 60.5%; abdominal ultrasound, 71.6%; barium meal, 48.1%; urine analysis, 90.1%; chest X-Ray, 69.1%; electrocardiogram, 74.1%; cardiac ultrasound, 75.3%). Risk factors for lack of AK were: place of residence (mammogram), age (Pap smear), personal income (sigmoidoscopy); risk factors for lack of CK included number of offspring (breast MRI, chest X-Ray), BMI (abdominal ultrasound), marital status (urine analysis), current smoking status (electrocardiogram). VABB's only effect was improvement in mammogram rates. Conclusions: A considerable lack of knowledge concerning screening tests and misperceptions regarding those without proven value was documented.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 사면안정 학술발표회
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• pp.155-180
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• 2000

The pattern of domestic slope construction has been steadily changed from the simpled and small-scale to the large-scale and complicated one, frequently near the existing structures, as the density of population and the traffic increases. In some cases, the slopes become steeper and larger due to the road improvement and construction. For the rock slope, the existence of discontinuity cannot be disregarded and acts as an important factor on the slope stability. Most of the existing methods for stabilizing the slope were focused on reducing the slope angle. Under the specific geographic condition, it is necessary to concentrate more efforts on the research and development of supporting system for the slope stability. As a supporting system, it is often very advantageous to use the FRP pipe grouting method that is similar to the existing soil nailing method or the rock bolting method but uses the high strength FRP pipe as a principal reinforcement in place of steel bar. Through the FRP pipe, the grout material can be injected into the rock mass to improve its shear strength to the required value. .In this study, the characteristics of FRP are investigated by the laboratory tests and the field tests. And, the practical aspects of FRP method are reviewed and analyzed.

• Computers and Concrete
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• 제24권2호
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• pp.95-102
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• 2019

Current article proposes a cheap prototype of an embedded wireless sensor to monitor concrete structures. The prototype can measure temperature and relative humidity concurrently at a controlled through smartphone time interval. It implements a maturity method to estimate in-place concrete strength, which is considered as an alternative for traditional shock impulse method and compression tests used in Kazakhstan. The prototype was tested and adequately performed in the laboratory and field conditions. Tests aimed to study the effect of internal and ambient temperature and relative humidity on the concrete strength gain. According to test results revealed that all parameters influence the strength gain to some extent. For a better understanding of how strongly parameters influence the strength as well as each other, proposed a multicolored cross-correlation matrix technique. The technique is based on the determination coefficients. It is able to show the value of significance of correlation, its positivity or negativity, as well as the degree of inter-influence of parameters. The prototype testing also recognized the inconvenience of Bluetooth control due to weakness of signal and inability to access several prototypes simultaneously. Therefore, further improvement of the prototype presume to include the replacement of Bluetooth by Narrow Band IoT standard.

• Geomechanics and Engineering
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• 제4권3호
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• pp.191-208
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• 2012

Due to rapid industrialisation, large scale infrastructure development is taking place worldwide. This includes railways, high speed highways, elevated roads etc. To meet the demands of society and industry, many innovative techniques and materials are being developed. In developed nations like USA, Japan etc. for railways applications, new material like geocells, geogrids are being used successfully to enable fast movement of vehicles. The present research work was aimed to develop design methodologies for improvement of grounds subjected to cyclic loads caused by moving vehicles on roads, rail tracks etc. Deformation behavior of ballast under static and cyclic load tests was studied based on square footing test. The paper presents a study of the effect of geo-synthetic reinforcement on the (cumulative) plastic settlement, of point loaded square footing on a thick layer of granular base overlying different compressible bases. The research findings showed that inclusion of geo-synthetics significantly improves the performance of ballasted tracks and reduces the foundation area. If the area is kept same, higher speed trains can be allowed to pass through the same track with insertion of geosynthetics. Similarly, area of machine foundation may also be reduced where geosynthetics is provided in foundation. The model tests results have been validated by numerical modeling, using $FLAC^{3D}$.