• 한국기계가공학회지
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• 제20권9호
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• pp.35-41
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• 2021

A rotor is a crucial component in various mechanical assemblies. Additionally, high-speed and high-efficiency components are required in the automotive industry, manufacturing industry, and turbine systems. In particular, the failure of high-speed rotating bearings has catastrophic effects on auxiliary systems. Therefore, bearing reliability and fault diagnosis are essential for bearing maintenance. In this work, we performed failure mode and effect analysis on bearing rotors and determined that corrosion is the most critical failure type. Furthermore, we conducted experiments to extract vibration characteristic data and preprocess the vibration data through principle component analysis. Finally, we applied a machine learning algorithm called support vector machine to diagnose the failure and observed a classification performance of 98%.

• Journal of Animal Science and Technology
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• 제56권6호
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• pp.22.1-22.7
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• 2014

The present study was performed to investigate the effects of two groups of sires with 'medium' and 'high' weight gain potentials (M-sires and H-sires, respectively) on growth of their progenies on varying planes of nutrition during the growing-finishing period. The ADG of the M-sires' progeny was greater (P < 0.05) than that of the H-sires' progeny (0.51 vs. 0.47 kg) during a 26- to 29-d early grower phase beginning from 55 d of age, but the opposite was true (0.66 vs. 0.72 kg) during the latter grower phase. Overall grower-phase ADG was greatest on the high plane of nutrition (H plane) followed by the medium (M) and low (L) planes (0.65, 0.61, and 0.51 kg, respectively; P < 0.05) in the M-sires' progeny, whereas in the H-sires' progeny, ADG was greater on the H and M planes vs. L plane (0.63, 0.62, and 0.54 kg, respectively). The ADG of pigs on the M or H plane during the grower phase and switched to the H plane thereafter (M-to-H or H-to-H planes) was greater than that of pigs on the L-to-L planes (0.99 vs. 0.78 kg) during the early finisher phase in the M-sires' progeny (P < 0.01). However, in the H-sires' progeny, ADG of pigs on the L-to-L planes did not differ from that of pigs on the M-to-M or H-to-M planes (0.94 vs. 0.96 kg). Results suggest that the H-to-H or H-to-M planes and M-to-M or M-to-L planes are optimal for maximal growth of the M- and H-sires' progenies, respectively.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.331-337
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• 2006

세계적으로 항만의 대형화, 첨단화, 효율화 등 항만환경의 변화가 급격하게 이루어지고 있으며, 선진항만들은 대륙별로 중심항만의 입지를 구축하기 위해 항만기술의 연구개발과 투자를 지속하고 있다. 항만의 대형화, 첨단화, 효율화에 대응하기 위해서는 지속적인 항만기술 개발이 필요하며, 이를 통해 자국 항만산업 발전과 더불어 세계 항만기술 관련 산업의 선점과 수출 극대화를 이룰 수 있을 것이다. 따라서 본 논문에서는 국내외 항만기술 개발의 현황과 추진정책을 살펴보고 항만기술 분야의 정립을 통해 국내 항만기술개발의 발전전략과 정책방향을 제시하고자 한다.

• 한국항해항만학회지
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• 제31권1호
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• pp.99-105
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• 2007

세계적으로 항만의 대형화, 첨단화, 효율화 등 항만환경의 변화가 급격하게 이루어지고 있으며, 선진항만들은 대륙별로 중심항만의 입지를 구축하기 위해 항만기술의 연구개발과 투자를 지속하고 있다. 항만의 대형화, 첨단화, 효율화에 대응하기 위해서는 지속적인 항만기술 개발이 필요하며, 이를 통해 자국 항만산업 발전과 더불어 세계 항만기술 관련 산업의 선점과 수출 극대화를 이를 수 있을 것이다. 따라서 본 논문에서는 국내외 항만기술 개발의 현황과 추진정책을 살펴보고 항만기술 분야의 정립을 통해 국내 항만기술개발의 발전전략과 정책방향을 제시하고자 한다.

• Fisheries and Aquatic Sciences
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• 제14권1호
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• pp.1-10
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• 2011

This study was conducted to obtain hydrolysates with potent antioxidative activity from rockfish skin gelatin. Gelatin was extracted under high temperature/high pressure using a two-step enzymatic hydrolysis with commercial enzymes such as Alcalase, Flavourzyme, Neutrase, and Protamex. The second rockfish-skin gelatin hydrolysate (SRSGH) was prepared by further incubating the first gelatin hydrolysate (FRSGH), which had been hydrolyzed with Alcalase for 1-h (FRSGH-A1), with Flavourzyme for 2-h (SRSGH-F2). The second gelatin hydrolysate showed higher antioxidative activity of 3.72 as measured by a Metrohm Rancimat and superior angiotensin I-converting enzyme (ACE) inhibiting activity of 0.82 mg/mL. Compared with the gelatin, the relative proportion in SRSGH-F2 was markedly decreased in the 100-kDa peak, whereas it was increased in that less than 100-kDa. The amino acid composition of SRSGH-F2 was rich in glycine (25.9%), proline (10.8%), alanine (9.1%), and glutamic acid (9.1%). In contrast, it was poor in cystine (not detected), methionine (1.6%), tyrosine (0.4%), hydroxylysine (0.9%), and histidine (0.9%). In recent years, demand for natural functional foods has been increasing, and SRSGH-F2 can be used as a functional food ingredient in the food industries. However, further detailed studies on SRSGH-F2 with regard to its antioxidant activity in vivo and the various antioxidant mechanisms are needed.

• Fisheries and Aquatic Sciences
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• 제14권3호
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• pp.168-173
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• 2011

The purpose of this study was to obtain a fraction with high antioxidative activity from second rockfish gelatin hydrolysates (SRSGHs), which were hydrolyzed with Alcalase and Flavourzyme through ultrafiltration membranes with serial digestions for 1 and 2 h, respectively, and to investigate the feasibility of this fraction as a potential functional food ingredient. Among various fractions that were ultrafiltered from the SRSGH with four types of membrane (1, 5, 10, and 30 kDa), the SRSGH-III fraction, which permeated the 10 kDa membrane but not the 5 kDa membrane, showed the highest antioxidant activity (protection factor=5.13) and angiotensin-I-converting enzyme-inhibiting activity ($IC_{50}$=0.82 mg/mL). These results suggest that the SRSGH-III fraction from the SRSGH can be used as a functional food ingredient. However, further studies examining its antioxidant activity in vivo as well as the different antioxidant mechanisms are needed.

• 산업경영시스템학회지
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• 제37권1호
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• pp.79-90
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• 2014

The Purpose of this study is to empirically examine the impact of various internal and external innovation activities of SMEs on their innovation performances in the field of electronics and communication industry. Drawing upon the literature review, internal and external innovation activities are defined and conceptualized, and independent, dependent and moderator variables are developed. We have used survey-based data for this study from the survey of technology innovation activities in manufacturing industry, which was conducted by the Science and Technology Policy Institute (STEPI) in 2010. The main result of this study shows that there were no significant differences in the impact of innovation activities on market performance according to the size of SMEs. On the other hands, we found that there were significant differences in the impact of innovation activities on technological innovation performance according to the size of SMEs. Therefore, in order to make high technological innovation performance, companies in the field of electronics and communication industry need to properly implement the internal and external innovation activities by considering their size.

• Fisheries and Aquatic Sciences
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• 제12권3호
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• pp.163-170
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• 2009

This study was conducted to obtain the gelatin fraction with a high anti oxidative activity from Alaska pollock surimi by-products using a two-step enzymatic hydrolysis and ultrafiltration. Among gelatin hydrolysates from refiner discharge of Alaska Pollock surimi, the highest antioxidative activity (81.5%) resulted from gelatin hydrolysate sequentially treated with Pronase E and Flavourzyme each for 2 hr. However, no difference was seen in the anti oxidative activity of the second hydrolysate (Pronase E-/Flavourzyme-treated hydrolysate) when compared to the permeate fractionated through a 10-kDa membrane. The results suggest that the Pronase E-/Flavourzyme-treated hydrolysate from refiner discharge gelatin of Alaska pollock surimi can be used as a supplementary raw material for improving health functionality.

• 기술혁신학회지
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• 제9권4호
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• pp.865-883
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• 2006

본 논문은 인터넷미디어산업의 발전요인을 분석한 연구로, 이 산업의 발전요인을 포괄적으로 설명할 수 있는 이론적 모형을 제시하고 이를 설문분석을 통해 확인한 것이다. 설문은 정책/기술/시장/기업/수익 요인 등 5개 분야에 걸쳐 촉진요인과 장애요인으로 구분하여 이루어졌다. 한편 각 요인과 이에 속한 항목들의 객관성을 확인하기 위해 응답에 근거해 인자분석을 시도하였고, 본 논문에서 제시한 5개 요인이 유용한 것으로 확인되었다. 이 산업의 발전은 기업요인과 수익요인 등 기업내적인 요인(41.3%), 기술/정책요인(37.6%)과 시장요인(21.0%)에 의해 영향 받는 것으로 파악되었다.

• 펄프종이기술
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• 제47권4호
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• pp.144-150
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• 2015

Stems of Pinus thunbergii Parl. grown with high salinity were analyzed for chemical characteristics. Stem of 2 years was rich in soluble compounds and stem of 3 years reduced the amount of the soluble compound. But, the lignin content have not seen a large change. Also, Klason lignins of stem of 2 and 3 years has not changed in nitrogen and hydrogen content. In Klason process, it was significantly increased the carbon concentration due to the hydrolysis of the carbohydrate. In addition, the accumulation of xylan from Pinus thunbergii Parl. with salinity treatment were increased noticeably. Finally, functional group of Pinus thunbergii Parl. with salinity treatment were not changed.