• 생명과학회지
• /
• 제28권7호
• /
• pp.795-801
• /
• 2018

본 연구는 제주마 체중 형질과 말의 3번 및 9번 염색체 단일염기변이마커간의 관련성을 분석하기 위해 수행되었다. 본 연구에 사용된 DNA 샘플은 제주특별자치도 축산진흥원에서 등록관리 중인 제주마 320두를 제공받았고, 생체중 자료는 한국마사회에서 시행한 경마에 출주한 제주마의 체중자료를 이용하였다. 기존에 말의 체형관련형질과의관련성이 보고된 바 있는 말의 3번 염색체상에 위치한 BIEC2-808466, BIEC2-808543, BIEC2-808967, BIEC2-809370 단일염기변이마커와 9번 염색체상에 위치한 BIEC2-1105370, BIEC2-1105372, BIEC2-1105377, BIEC2-1105505 and BIEC2-1105840 유전자형을 분석하였다. 관련성 분석을 위한 종속변수는 선형혼합모형을 이용해서 추정한 생체중 육종가를 이용하였다. 관련성 분석결과 6개의 마커(BIEC2-808543, BIEC2-808967, BIEC2-809370, BIEC2-1105370, BIEC2-1105372, and BIEC2-1105377)와 생체중 추정육종가간의 유의성이 인정되었다. 또한, BIEC2-808967과 BIEC2-1105377의 유전자형조합을 구성하여 생체중 추정육종가에 대한 효과를 분석한 결과, 두 마커의 유전자 조합은 생체중 변이에 유의한 효과가 있었다. 본 연구에서 유의성이 인정된 단일염기변이마커들은 제주마의 체중 개량을 위한 선발육종체계의 효율성을 높일 수 있는데 사용될 수 있을 것으로 사료되지만, 이 들 마커효과의 좀더 정확한 추정을 위한 추가의 연구가 필요할 것으로 생각된다.

• 한국화재소방학회논문지
• /
• 제31권4호
• /
• pp.65-70
• /
• 2017

본 연구는 최근 수계소화설비 배관에 적용되고 있는 스테인리스 강관용 프레스식 관이음쇠에 대한 내진성능 연구를 수행한다. 연구를 위한 설비의 구성은 NFPA 13의 배관연결방법으로 하였다. 배관의 허용변위량은 건축구조기준에서 제시한 허용량으로 하였고, 반복회수는 10회로 하였다. 실험 후 배관의 Von-mises 응력은 허용응력의 2.48, 1.25배로 NPPs Allowable Stress for Level D service loading의 "허용응력의 3배"인 기준 보다는 적게 나타났다. 따라서 프레스식 관이음쇠는 내진성능을 갖추고 있는 것으로 판단 할 수 있다.

• 한국안전학회지
• /
• 제34권2호
• /
• pp.40-47
• /
• 2019

The Half-depth precast deck is a structural system that utilizes pre-cast panels pre-built at the factory as formwork at the construction stage and as a major structural member at the same time after completion. These systems have joints between segments, and the detail and performance of the joints are factors that have a very large impact on the quality, such as the constructability and durability of the bridge decks. In this study, strength performance evaluation was performed for improved joints using connecting rebar by experimental method. Static loading tests were conducted on the test specimen with improved joint, those with existing joint and those without joint. The test results of the specimens were compared to each other, and the flexural strength required by the design was compared. The flexural strength required in the design was presented by finite element analysis. It has been shown that the flexural strength of the specimens with joints were more than twice that required by the design. But the flexural strength of the specimen with existing joint was about 84% of that without joint. The flexural strength of the specimen with improved joints was a nearly similar degree of that compared to the specimen without joint. And a comparison of the moment-deflection relationship curves of the two specimens also shows a very similar flexural behavior. It is confirmed that improved joint has sufficient flexural strength. In addition to strength, the bridge decks require serviceability, such as deflection and cracking, and in particular, fatigue resistance due to repetitive live loads is an important performance factor. Therefore, further verification studies are required.

• 대한산업공학회지
• /
• 제12권1호
• /
• pp.147-155
• /
• 1986

Nations, especially developing countries, hope to license the technology developed at the expense of government Research and Development (R&D) investment to the corresponding firms for commercial exploitation. Since commercial process is owing to lots of risk, firms have to grope the possibility of forming a partnership in order to reduce the risk. Therefore, a joint venture between firms would be needed to share the risk. This methodology suggests a way that probabilistic information of commercial project payoffs can be obtained using experts in project evaluation committee and the ratio of individual firm's investment size can be derived using risk sharing concept. Also simple examples are given.

• 한국안전학회지
• /
• 제33권5호
• /
• pp.70-77
• /
• 2018

In this study, the reinforced methods of joints were proposed to improve the structural performance of the enhanced spun reinforced concrete piles with joints. To verify the proposed methods, flexure performance was validated by finite element analysis considering both material and contact nonlinearity. Based on the previous study and those results of the analysis, it is concluded that the structural performance of the current joints system for the enhanced spun RC piles can be enhanced by applying the reinforced joints composed of extended circular band plates and studs. This proposed method showed the nearest structural behavior to the enhanced spun RC piles without joints. This numerical study will be used to further experimental study on the enhanced spun RC piles with reinforced joints.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2008년도 춘계학술발표대회 개요집
• /
• pp.30-30
• /
• 2008

• Applied Microscopy
• /
• 제45권2호
• /
• pp.89-94
• /
• 2015

This article briefly reviews the results of recently reported research on high-temperature Pb-free solder alloys and the research trend for characterization of the interfacial reaction layer. To improve the product reliability of high-temperature Pb-free solder alloys, thorough research is necessary not only to enhance the alloy properties but also to characterize and understand the interfacial reaction occurring during and after the bonding process. Transmission electron microscopy analysis is expected to play an important role in the development of high-temperature solders by providing accurate and reliable data with a high spatial resolution and facilitating understanding of the interfacial reaction at the solder joint.

• Journal of Welding and Joining
• /
• 제34권2호
• /
• pp.30-35
• /
• 2016

Last few decades have seen a rapid increase in the fabrication and characterization of Al alloys for automobiles, heat exchangers and aerospace industries. Aluminium alloys are popular because of their high specific strength, light weight, excellent wear and high oxidation resistance. The development of aluminium alloys in these applications makes their study and research of utmost importance. Brazing is applied to the aluminium alloys for joining various aluminium parts together in most of the industrial applications. Various parameters affect the joining process of these aluminium alloys. In this article, various types of processing parameters have been discussed, and special attention has been given to the category of aluminium brazing alloys. The article reviews on the various parameters that affect the brazing property in various scientific and technological applications.

• Interaction and multiscale mechanics
• /
• 제6권2호
• /
• pp.257-270
• /
• 2013

The use of lightweight materials has been steadily increasing in the automotive industry, and presents new challenges to material joining. Among many joining processes, self-piercing riveting (SPR) is particularly promising for joining lightweight materials (such as aluminum alloys) and dissimilar materials (such as steel to Al, and metal to polymer). However, to establish a process window for optimal joint performance, it often requires a long trial-and-error testing of the SPR process. This is because current state of the art in numerical analysis still cannot effectively resolve the problems of severe material distortion and separation in the SPR simulation. This paper presents a coupled meshfree/finite element with a moving boundary algorithm to overcome these numerical difficulties. The simulation results are compared with physical measurements to demonstrate the effectiveness of the present method.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제13권1호
• /
• pp.707-717
• /
• 2021

To the date, shipbuilding companies have applied shop primer coating which protects the steel surface from global oxidization in environment. Proper shop primer requires either anti-corrosion ability during construction or anti-porosity ability during welding, and those properties contradict to each other. This report tried to derive an optimizing parameter on these conflicting properties to select a proper shop primer. First, sufficient amounts of the natural salt spray tests were carried out to achieve a series of data for the anti-corrosion ability. Second, lots of T-joint fillet welding test were performed to evaluate the trapped porosity formed in the weld pool. According to the experimental data, we could achieve either the rust-formation rate or the porosity-formation rate, then, each rate was generalized as formulae. Then, we tried to combine these conflicting properties to decide an optimum shop primer.