• Corrosion Science and Technology
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• 제13권2호
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• pp.62-69
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• 2014

A huge number of carbon steel piping components installed in the secondary system of nuclear power plants are exposed to aging mechanisms such as FAC (Flow-Accelerated Corrosion), Cavitation, Flashing, and LDIE (Liquid Droplet Impingement Erosion). Those aging mechanisms can lead to thinning of the piping components. To manage the wall thinning degradation, most of utilities in the world predict the wall thinning rate based on the computational program such as CHECWORKS, COMSY, and BRT-CICERO, evaluate the UT (Ultrasonic Test) data, and determine next inspection timing, repair or replacement, if needed. There are several evaluation methods, such as band, blanket, and strip methods, commonly used for determining the wear of piping components from single UT inspection data. It has been identified that those single UT evaluation methods not only do not consider the manufacturing features of pipes, but also may exclude the data of the most thinned point when determining the representative wear rate of piping components. This paper describes a newly developed single UT evaluation method, E-Cross method, for solving above problems and introduces application examples for several pipes and elbows. It was identified that the E-Cross method using the length and width of UT data excluded the most thinned points appropriate as the single UT evaluation method for thinned piping components.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2005년도 ISMP
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• pp.67-88
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• 2005

Mold-Flow 3 Die Stack CSP of Mold array packaging with different Gate types. As high density package option such as 3 or 4 die stacking technologies are developed, the major concerning points of mold related qualities such as incomplete mold, exposed wires and wire sweeping issues are increased because of its narrow space between die top and mold surface and higher wiring density. Full 3D rheokinetic simulation of Mold flow for 3 die stacking structure case was done with the rheological parameters acquired from Slit-Die rheometer and DSC of commercial EMC. The center gate showed severe void but corner gate showed relatively better void performance. But in case of wire sweeping related, the center gate type showed less wire sweeping than corner gate types. From the simulation results, corner gate types showed increased velocity, shear stress and mold pressure near the gate and final filling zone. The experimental Case study and the Mold flow simulation showed good agreement on the mold void and wire sweeping related prediction. Full 3D simulation methodologies with proper rheokinetic material characterization by thermal and rheological instruments enable the prediction of micro-scale mold filling behavior in the multi die stacking and other complicated packaging structures for the future application.

• Computers and Concrete
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• 제16권6호
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• pp.847-864
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• 2015

This study aimed to develop models of sulfate diffusion and ettringite content profile in cement paste for the predication of the damage behavior in cement paste subject to external sulfate. In the models, multiphase reaction equilibrium between ions in pore solution and solid calcium aluminates phases and the microstructure changes in different positions of cement paste were taken into account. The distributions of expansive volume strain and expansion stress in cement paste were calculated based on the ettringite content profile model. In addition, more sulfate diffusion tests and SEM analyses were determined to verify the reliability and veracity of the models. As the results shown, there was a good correlation between the numerical simulation results and experimental evidences. The results indicated that the water to cement ratio (w/c) had a significant influence on the diffusion of sulfate ions, ettringite concentration profile and expansion properties in cement paste specimens. The cracking points caused by ettringite growth in cement paste specimens were predicted through numerical methods. According to the simulation results, the fracture of cement paste would be accelerated when the specimens were prepared with higher w/c or when they were exposed to sulfate solution with higher concentration.

• 한국의류산업학회지
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• 제15권1호
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• pp.95-102
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• 2013

In order to understand meaningful customer experience in social media, this study profiles customer engagement by exposing the essential brand experience rooms in hyper-reality contexts. This study selects Snuggie as a target brand as it uses multiple contact points, including social media, to provide meaningful experience to customers. With their unique marketing strategy, Snuggie became a popular brand among the U. S. customers beyond just a wearable blanket. Upon analyzing a total of 364 customer reviews about Snuggie in Amazon.com, five experience rooms were exposed; "Physical artifacts" and "customer involvement" are influential experience rooms which signify interactions between products and customers, while "intangible artifacts", "technology" and "customer placement" reflect a lower degree of experiential engagement. This approach suggests a theoretical foundation in understanding the customer engagement concepts by the means of brand experience dimensions in social media. The ability to create compelling engagement in social media depends on the successful facilitation of relationships and information, which lead to a creative, communicative and interactive experience.

• Journal of Biosystems Engineering
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• 제15권3호
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• pp.177-185
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• 1990

The break of rotary blade is occured from a stress concentration of the inside of blade by the outside impulsive load. In order to examine its inside stress and stress concentration of rotary blade, a epoxy plate which is suitable to applicate by photoelastic system is used to experiment. These results are summarized as follow. 1. Refer to the existence of bolt hole and a size of its of rotary blade, a stress concentration which cause the break of rotary blade is not exposed. 2. It is expected to be break to section of hold of rotary blade and the break of this is due to that there are concentrated by shearing force, bending moment and bending stress. 3. When the crack which caused from processing are set up to any location, the stress concentration taken to the creak point. 4. Without regard to the location of the reaction points of rotary blade, the bending stress which is greated than the bending moment is occured within about 6 em toward the center line of bolt hole and it was possible to break that section.

• Restorative Dentistry and Endodontics
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• 제9권1호
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• pp.127-132
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• 1983

The purpose of this study was to examine the sealing ability of the vitapex, when used with gutta-percha cone, as a root canal filling material. Fourty five canals from extracted human maxillary and mandibular teeth were randomly selected and instrumented in a conventional method with k-file. After instrumentation and dry the canal with paper points, the canals were divided into three groups and fifteen canals in each group were filled with the following materials; Vitapex, Vitapex in combination with gutta-percha cone, and Gutta-percha cone and Zinc-oxide Eugenol Cement. All the specimens were immersed in 2% methylenblue dye solution and the depth of dye penetration into the canals were evaluated by macroscope at the intervals of 1 day, 2days and 7days. The following results were obtained; 1. All the materials experimented showed varying degrees of dye penetration. 2. The canals filled with Vitapex and Vitapex in combination with gutta perch a cone revealed sudden increase of dye penetration with time passage compared to the canals obturated with Gutta-percha cone and Zinc-oxide eugenol cement. 3. In the canals filled with Vitapex, the mean dye penetration was 1.6mm at 1day, but the specimen exposed to the dye for 7days showed mean dye penetration of 9.2mm. 4. In the canals obturated with Vitapex and gutta-percha cone, the mean dye penetration was 2mm at 1day, 2.2mm at 2days, and 8mm at 7days.

• Journal of Korean Neurosurgical Society
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• 제54권3호
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• pp.253-256
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• 2013

Spinal intradural hemangiopericytoma is a very rare tumor and can be characterized by massive bleeding during surgeries, frequent recurrence, and metastasis. However, definite radiologic differential points of hemangiopericytoma are not known. We describe an unexpected hemangiopericytoma case with large bleeding and management of the tumor. A 21-year-old man visited complaining of progressive neck pain and tingling sensation in both hands. Magnetic resonance imaging of his spine revealed C1-2 ventral intradural mass. When the dura was opened, the intradural tumor was placed behind spinal accessary nerves. The tumor was partially exposed only after some accessary nerves had been cut. When internal debulking was performing, unexpected bleeding was noted and it was difficult to control because of narrow surgical field and hypervascularity. Intraoperative spinal angiography and embolization were performed. The tumor was completely removed after embolization. Pathological diagnosis was consistent with hemangiopericytoma. When surgeons meet a flesh-red tumor that bleeds unexpectedly during surgery, hemangiopericytoma may be considered. When feeder control is hard due to reciprocal location of spinal cord, the tumor, and feeders, intraoperative angiography and embolization may be a possible option.

• Journal of Microbiology and Biotechnology
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• 제30권1호
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• pp.101-108
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• 2020

Infections by herpes simplex viruses have an immense impact on humans, ranging from self-limiting, benign illness to serious, life-threatening diseases. While nucleoside analog drugs are available, resistance has been increasing and currently no vaccine exists. Ginsenosides derived from Panax ginseng have been documented to inhibit several viruses and bolster immune defenses. This study evaluated 12 of the most relevant ginsenosides from P. ginseng for toxicities and inhibition of herpes simplex viruses types 1 and 2 in Vero cells. The effects of test compounds and virus infection were determined using a PrestoBlue cell viability assay. Time course studies were also conducted to better understand at what points the virus life cycle was affected. Non-toxic concentrations of the ginsenosides were determined and ranged from 12.5 μM to greater than 100 μM. Ginsenoside 20(S)-Rg3 demonstrated the greatest inhibitory effect and was active against both HSV-1 and HSV-2 with an IC₅₀ of approximately 35 μM. The most dramatic inhibition-over 100% compared to controls-occurred when the virus was exposed to 20(S)-Rg3 for 4 h prior to being added to cells. 20(S)-Rg3 holds promise as a potential chemotherapeutic agent against herpes simplex viruses and, when used together with valacyclovir, may prevent increased resistance to drugs.

• 유통과학연구
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• 제15권1호
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• pp.51-56
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• 2017

Purpose - The study verified the effects of consumers' knowledge perception upon word-of-mouth intention and purchase intention of consumers who were exposed to a lot of information, and examined consumer's behavior from multi-dimensional points of view. Research design, data, and methodology - The study conducted the test of difference between consumer's cognition on importance and satisfaction of HMR product by gap of HMR (Home Meal Replacement) product for IPA analysis. The consumer's reliability and words-of-mouth were measured by the questionnaire method with 4 questions according to Likert 7-point scale. Conversion into z-score removed the difference of variables. Results - The causal relation model for importance, satisfaction and gap, not relying upon multi-dimensional scaling and others, could construct causal relation model to give implications. Difference (d) of the products could lessen consumer's reliability to increase consumer's knowledge perception, word-of-mouth intention, knowledge perception, and purchase intention. Therefore, enterprises should make an effort to lessen consumers' complaint for the products and to elevate consumers' reliability. Enterprises also try to give consumers exact information and to promote purchase intention. Conclusions - Difference (d) of consumers' complaint and/or disappointment decreased consumers' reliability to increase knowledge perception. Enterprises should supply consumers with products according to their requirements to minimize the gap and to give them proper information.

• 한국건설관리학회논문집
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• 제6권5호
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• pp.177-185
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• 2005

건설공사의 불확실성은 빈번히 클레임에 노출된다. 대부분의 경우 이러한 클레임에 대한 기본적인 해석은 공사계약서를 기준으로 하게 된다. 이러한 계약서 작성시의 문제는 발주자나 시공자가 부담하여야 하는 계약적 위험(risk)이 어떻게 규정되어 있어야 합리적인 수준인가를 판단하는 것인데 이러한 판단을 위해서는 FIDIC 계약조건과 같이 국제적으로 합리성을 인정받는 표준계약조건을 참고하는 것이 합리적이라 하겠다. 이에 본 연구는 FIDIC 계약조건을 기준으로 국내 공공공사에서 일반적으로 사용하는 공사계약일반조건에 내재되어 있는 불공정, 불합리 조항을 분석하여 세계적 수준에 맞는 공사계약조건을 제시하고자 위험관리의 관점에서 공사 계약조건을 분석하고, 여기서 도출되는 위험요인을 검증하며, 이에 대한 대응방안을 모색함으로써 공사계약일반조건의 위험요인 감소방안을 제시하고자 한다.