• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.2
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• pp.83-91
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• 2017

In order to cope with the abnormally high waves during the storm surge due to climate change, various methods have been proposed for interlocking adjacent caissons to enhance stability of harbor structures. Among the methods, it was studied the method based on an open-cell caisson having reduction effect increasing the cohesion with adjunction caissons by filling materials such as crushed rocks in an inter-cell formed by two facing open-cells which consist of transverse walls. It is necessary to investigate the shear behaviors of an inter-cell to secure the stability using calculating shear forces on inter-cell under oblique wave loadings. It was analyzed the shear force share ratio with the length of internal and external wall and the number of internal walls. Numerical results show that 60~70% of the shear load is transmitted to adjacent caisson through the internal walls, more than 30% is through the external wall. It was applicable in the assumption that filling materials was uniformly distributed in inter-cells, and further studies were worth consideration on other conditions under construction.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.364-368
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• 2004

Micro Cellular Plastics create a sensation at polymer industrial for lowering product cost & overcoming a lowering of mechanical intensity. This research based on the experiment of sound absorption & transmission characteristics inquire into acoustic property of Micro Cellular Plastics. This experiment clarify the change of cell foaming rate for foaming time and the change of sound absorption & transmission for foaming rate.

• Journal of Venture Innovation
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• v.5 no.2
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• pp.85-99
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• 2022

Dryers becoming commercially available for experimental and industrial use are classified to general drying oven, hot-air dryer, vacuum dryer, freezing dryer, etc. and kinds of them are various from the function, size and volume, etc. But the moisture measurement is not applied although it is important factor for the quality control and the performance improvement of products, and then now is very passive because the weight is weighed arbitrarily after dry-end. Generally the method for measuring moisture is divided by a direct measurement method and a indirect measurement method, and the former such as the change of weight or volume on the front and rear of separation of moisture, etc. is mainly used. Relatively a indirect measurement is very limited to apply due to utilize measurement apparatuses using temperature conductivity and micro-wave etc. In this research, we easily designed the moisture measurement system using the open-source based Arduino, and monitored moisture fluctuations and weight profiles in the real-time without the effect of external environment. Concretely the temperature-humidity and load cell sensors were packaged into a drying oven and the various change values were measured, and their sensors capable to operate 60℃ and 80℃ were selected to suitable for the moisture sensitive materials and the food dry. And also the performance safety using the organic samples of banana, pear, sawdust could be secured because the changes of evaporation rate as the dry time and temperature, and the measurement values of load cell appeared stable response characteristics through repeated experiments. Hereafter we judge that the reliability can be improved increasingly through the expansion of temperature-humidity range and the comparative analysis with CFD(Computational Fluid Dynamics) program.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.32-37
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• 2014

Open-cell silicon foam is difficult to cut using conventional machining processes because of its low stiffness. That is, open-cell silicon foam is easily pressed down when the tool is engaged, which makes it difficult to remove the material in the form of chip. This study proposes an advanced method of machining open-cell silicon foam by freezing the material using liquid nitrogen. Furthermore, the machining conditions are optimized to maximize the efficiency of material removal and minimize the usage of liquid nitrogen by conducting experiments under various machining conditions. The results show that open-cell silicone foam products with free surface can be successfully machined by employing the proposed method.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.201-203
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• 2019

5G 시스템은 혁신적인 발전을 거듭하며 강력해진 기술 표준을 근간으로 초광대역 이동형 데이터 서비스, 대규모 사물통신 서비스 등을 제공하고 있다. 본 논문에서는 SW를 기반으로 한 5G의 기술 개발 방법론을 제안한다. 또, 실제 환경에서 차세대 모바일 네트워크의 성능 분석이 가능한 SW 기반의 시스템 레벨 테스트베드 및 모니터링 프로그램을 OAI(Openairinterface) 5G 연구 단체의 오픈소스를 이용하여 구현한다. 기존 하드웨어 위주의 단일 칩 시스템(SoC)을 이용한 구현은 손상되기가 쉽고 유지보수가 힘들다는 단점이 있다. 하지만 기존 하드웨어 칩을 소프트웨어 기반인 소스코드로 구현하면 유지 보수가 용이하다는 장점뿐만 아니라 하드웨어가 변경되더라도 다른 하드웨어에 호환되는 이식성 때문에 생산성이 높아지며 비용 절감의 효과도 기대할 수 있다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.60-66
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• 2016

Polyurethane foam index a of the cell structure and the absorption change by using the foam stabilizer of six to investigate the polyurethane foam index producing the agent to the siloxane analyzed with silicon foam stabilizer with FE-SEM in accordance with the characteristics of the silicon-based foam stabilizer cell structure of the primary DC-193 on the chain ends is PO n dog bond, DC-2585, DC-5125, DC-198 has been confirmed as a close cell, silicone surfactant is combined EO n dog to a siloxane main chain terminus DC-5043 and DC-5598 that appeared to open cell structure. In addition, most absorption of the DC-5043 appeared was the size of the open cell greatest formed by the absorption of the cell structure change this absorption of the size of the close cell most detailed and uniform DC-193 appeared small household water-resistant best many showed. The performance test of the water was found to be excellent.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.632-639
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• 2011

Searching distributed resource efficiently is very important in distributed computing, cloud computing environment. Distributed resource searching may have system overheads and take much time in proportion to the searching number, because distributed resource searching has to circuit many peers for searching information. The open-source community project JXTA defines an open set of standard protocols for ad hoc, pervasive, peer-to-peer computing as a common platform for developing a wide variety of decentralized network applications. In this paper, we proposed peer search algorithm based on JXTA-Sim. original JXTA peer searching algorithm selected a loosely-consistent DHT. Our Lookup algorithm decreases message number of WALK_LOOKUP and reduce the network system overload, and we make a result of same performance both original algorithm and our proposed algorithm.

• KSBB Journal
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• v.18 no.5
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• pp.412-417
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• 2003

We first investigated basic characteristics of reticulated polyurethane (PU) foams as microbial carriers. In general, the specific surface area of PU foams increases with respect to decreasing pore sizes. However, the number of microbes adhered on the unit surface of reticulated PU foams decreases with respect to decreasing pore sizes. Thus, as a result of totally considering all effects such as apparent density, hydrolysis rate, and adhesion, we can know that PU foams with 45 PPI is the most appropriate microbial carrier. In this study, we can also investigate the effect of various physico-chemical surface treatments on the adhesion of microbes on the surface of PU foams. We used a chitosan treatment, a PEI (Polyethylene Imine) treatment, a xanthane treatment and a plasma treatment. As a result of comparing all surface treatments, the plasma surface treatment was the best.