• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1992.10a
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• pp.59-64
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• 1992

터빈 블레이드와 같이 회전하는 구조물의 파단은 공진 근처에서 진동이 발 생할 때에 이에 기인하는 피로에 의하여 발생한다. 그러므로 이와 같은 파단 을 피하기 위해서는 설계 단계에서 이론적인 계산에 의하여 구조물의 고유 진동수를 결정하는 것이 상당히 중요하다. 판이 회전을 받게 되면 원심력에 의하여 판의 강성이 증가하므로 고유진동수가 회전하지 않는 판의 고유진동 수보다는 상당히 증가하게 된다. 이에 대한 연구가 국내외에서 상당수 행하 여졌지만, 연구의 대부분이 회전의 영향을 고려하지 않은 정지판(stationary plate)에 대한 것이며 뢰전을 고려한 연구는 극히 제한되어 있다. 또한 회전 의 영향을 고려한 연구의 대부분이 해석 대상을 보로서 단순화 시켰고 해법 으로는 유한요소법과 Ritz법 등을 사용하였다. 이는 블레이드가 지니고 있는 기하학적인 형상과 진동 특성이 해석적인 방법으로 해결하는 데에는 상당한 어려움이 있기 때문이다. 실제적으로는 터빈 블레이드와 같은 회전체의 진동 특성이 설치각이나 비틀림각, 판의 형상비, 회전속도 등의 변화에 의하여 영 향을 받기 때문에 보와 같은 진동 거동을 보이기보다는 판이나 셀과 같은 진동 거동을 보이므로 보다 정확한 해석을 수행하기 위해서는 해석 대상을 판이나 셀로서 취급하는 것이 타당하다. 따라서 본 연구에서는 위와 같은 이 유 때문에 해석 대상을 등방성 사각판과 직교이방성 복합재료 사각판으로 선택하였으며, 구조물의 고유진동수에 영향을 미치는 다음과 같은 인자들을 해석에 고려하였다. 1. 회전속도 (rotational speed) 2. 설치각 (setting angle) 3. 허브의 반경 (hub radius) 4. 판의 형상비 (aspect ratio) 5. 적층순서 (stacking sequence)구조물에 대한 동적실험(dynamic test)을 통하여 단기간에 동적특성을 결정하고 SDM(structure dynamic modification)이나 FRS(force response simulation)를 수행하여 임의의 좌표 공간에 대한 진동수준을 해석적으로 예측할 뿐만 아니라 구조물의 진동제어 를 위한 동적인자를 변경시킬 수 있는 정보를 제공하며 장비를 방진할 경우 신뢰성 있는 전달률을 결정할 수 있다. 실험적으로 철교, 교량이나 건물의 철골구조 및 2층 바닥 등 대,중형의 복잡한 구조물에 대항 동특성을 나타내 는 모빌리티를 결정할 경우 충격 가진 실험이 사용되는 실험장비 측면에서 나 실험을 수행하는 과정이 대체적으로 간편하다. 그러나 이 경우 대상 구조 물을 충분히 가진시킬수 있는 용량의 대형 충격기(large impact hammer)가 필요하게 된다. 이러한 동적실험은 약 길이 61m, 폭 16m의 4경간 교량에 대 하여 동적실험을 수행하여 가능성을 확인하였다. 여기서는 실험실 수준의 평 판모델을 제작하고 실제 현장에서 이루어질 수 있는 진동제어 구조물에 대 한 동적실험 및 FRS를 수행하는 과정과 동일하게 따름으로써 실제 발생할 수 있는 오차나 error를 실험실내의 차원에서 파악하여 진동원을 있는 구조 물에 대한 진동제어기술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but stron

• Journal of Animal Science and Technology
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• v.49 no.3
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• pp.321-328
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• 2007

Two pig trials were conducted to test Herb MixⓇ, a mixture of Rehmannia glutinosa, Angelica gigas, Discorea japonica, Glycyrrhiza uralensis, Schisandra chinensis and Ligusticum jeholense, as a herbal additive to weaning pig diet. Exp. 1 was conducted with 45 three-way cross-bred(Y×L×D) weaning pigs randomly allocated to 3 treatments; control, Herb MixⓇ 0.15% and Herb MixⓇ Gold(Plellidendron amurense fortified Herb MixⓇ) 0.15%. Exp. 2 was conducted with 48 weaning pigs randomly allocated to 4 treatments; control, 0.1%, 0.2% and 0.3% Herb MixⓇ. There was a significant(p=0.05) difference between the control and herbal additive groups, however, no significant difference was found between Herb MixⓇ and Herb MixⓇ Gold in growth performance of Exp. 1. In Ex. 2, supplementation of Herb MixⓇ at all level(0.1%, 0.2% and 0.3%) significantly(P<0.05) improved average daily gain and feed intake, however, there were no significant differences among supplemented groups. Among the blood parameters, serum IgG level and WBC numbers were significantly lowered by Herb Mix supplementation in both experiments. Stress indicator(SI) was significantly lower in herbal additive groups in Exp. 1. Nutrient digestibility of DM and NFE in supplemented groups was lower than the control in Exp. 1. Howener, it was not significantly different among treatments in Exp. 2. Number(cfu) of fecal E.coli decreased while that of Lactobacilli increased in treated groups. It was concluded that fortifying Herb MixⓇ with Plellidendron amurense was not effective in improving the efficacy of Herb MixⓇ and supplementation of Herb MixⓇ at 0.1~0.2% level improves growth performance of weaning pigs. Blood parameters especially immunity related ones(IgG, WBC and SI) were significantly influenced.

• The Korean Journal of Air & Space Law and Policy
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• v.19 no.2
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• pp.97-136
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• 2004

The Northeast Asian air cargo market has expanded tremendously as a result of the opening up of the Chinese market. The importance of the Asia-Pacific region in the global air transport has also increased. The exchange of human and material resources, services, and information in Northeast Asia, which is expected to increase in the near future, requires that the airlines operating within this region adopt a more liberalized approach. This paper introduced alternatives which can be applied to the Northeast Asian airlines industry so as to bring about the integration of regional air transport: First, this paper found a need for individual Northeast Asian nations to alter their policies towards the airlines industry. Second, each country should further liberalize their respective domestic air transport. Third, there is a need for freer air service agreements to be signed between the nations of Northeast Asia. Fourth, the strategic alliances between the airlines operating in Northeast Asia should be further strengthened. Fifth, this liberalization process should be carried out in an incremental manner, beginning with more competitive airports and routes, or with less-in-demand routes. Sixth, there is a need for a shuttle system to be put into place between the main airports in China, Korea, and Japan. Seventh, these three nations jointly develop aviation safety and security systems that are in accordance with international standards. Eighth, the liberalization process of the aviation industry should be undertaken in conjunction with other related fields. Ninth, organizations linking together civil aviation organization in the Asia-Pacific area should be formed, as should each government linking together. By doing so, these countries will be able to establish regular venues through which to exchange opinions on the integration and liberalization of the air cargo market so as to induce the gradual liberalization of the actual market. The liberalization of the air transport in Northeast Asia will prove to be a daunting task in the short term. However, if the Chinese airlines continue to exhibit continuous growth and Japanese airlines are able to complete their move towards a low-cost structure, this process could be completed earlier than expected. Over the last twenty five years the air transport has undergone tremendous changes. The most important factor behind these changes has been the increased liberalization of the market. As a result, rates have decreased while demand has increased. This has resulted in turning the air transport industry, which was long perceived as an industry in decline, into a high-growth industry. The only method of increasing regional exchanges in the air transport is to pursue further liberalization. The country which implements this liberalization process at the earliest date may very well emerge as a leading force within the air transport industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.105-110
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• 2009

The effects of heat treated and herb added garlic (Allium sativum L.) on the antioxidant activities were investigated. Boiling ($100^{\circ}C$, 60 min), steaming ($100^{\circ}C$, 30 min), baking ($120^{\circ}C$, 10 min), or high temperature and high pressure (HTHP, $120^{\circ}C$, 20 min, 1.5 kgf/$cm^2$) were applied, and several herbs were added to garlic. Hunter color L-value of heated garlic was significantly decreased, compared to that of control (fresh garlic), whereas a-value and b-value were increased (p<0.05). In the texture profile analysis, hardness, chewiness and gumminess of heated garlic were decreased, whereas adhesiveness was increased. The antioxidant activities determined by DPPH and hydroxyl radical scavenging activities were decreased in HTHP garlic. The pungent taste and garlic odor were the weakest in HTHP garlic. Especially, the pungent taste of HTHP garlic was not detectable. Green tea among several herbs (bay leaf, cinnamon bark, pine needles) showed the highest DPPH radical scavenging activity. Addition of green tea to HTHP garlic was appropriate for decreasing antioxidative activity of HTHP garlic compared to fresh garlic. Based on these results, it was suggested that high temperature and high pressure treated garlic with green tea might be very useful as a substitute for odorless functional garlic products.

• Journal of the Korea Convergence Society
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• v.10 no.3
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• pp.167-176
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• 2019

The conversational agent, which is at the forefront of the 4th industry, aims to personalize the user-centered focus in the future and holds an important position to have a hub that can be connected to various IoT devices. It is a challenge for interactive agents to recognize the user's emotions and provide the correct interaction to personalization. The study first I looked at emotional definitions and scientific and engineering approaches. Then I recognized through social perspectives what social function and what factors emotions have and how they can be used to understand emotions. Based on this, I explored how users can be discovered emotional social factors in communication. This research has shown that social factors can be found in the user's speech, which can be linked to the social meaning of emotions. Finally, I propose a model to discover social factors in user communication. I hope that this will help designer and researcher to study user-centered design and interaction in designing interactive agents.

• Journal of Practical Engineering Education
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• v.9 no.1
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• pp.69-75
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• 2017

In this paper, we analyzed the factors influencing the size of Korea Polytechnic as a public vocational education and training institution through analysis of demand, region, industry, and demand with established existing campus and new campus in Korea Polytechnic. By analyzing data on admission, training, and employment for 3 years out of 37 campuses, we have sampled 5 campuses by type of Korea Polytechnic, fused with the results derived from the literature analysis and in-depth analysis results, so that the regional campus will play a leading role and the direction of development. The selection of five campuses by type is a precedent study to analyze 37 campuses in the future. As a result of the study, the demand analysis through objective indicators such as the number of high school graduates, the number of employed persons, the presence of nearby industrial complexes, and policy variables is very important and reflects the reality well. Therefore, it is necessary to analyze the demand through the objective indicators in decision making related to the new campus at the pre-analysis stage. In addition to the general data proposed in this paper, that is, common variables in all regions, it is important to consider the factors that can reflect local demand characteristics when considering specific locations.

• Journal of Apiculture
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• v.34 no.3
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• pp.197-206
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• 2019

Pollination is an important ecosystem service involved in plant breeding and reproduction. This study analyzed the pollination network, which is the interaction between flowering plants and flower-visiting insects in the agricultural landscape. Flower-visiting insects from blossoms of flowering crops and surrounding plants were quantitatively surveyed during summer time. The pollinator species and abundance on each flowering plant were analyzed. A total of 2,381 interactions were indentified with 154 pollinators on 30 species of plants. Species richness of the pollinators was highest in Coleoptera (34%) followed by Hymenoptera (28%), Diptera (28%) and Lepidoptera (10%). Apis mellifera dominated (50%) followed by Calliphora vomitoria (5.3%) and Xylocopa appendiculata among pollinators, and remaining wild pollinators provided complex interaction. Among plants, Platycodon grandiflorum, Perilla frutescen and Fagopyrum esculentum harbored most pollinators and showed highest interaction frequencies. In the modular analysis, Apis mellifera was located as a hub-species which connect the interaction of others, implying most important role in the network. This results provide the basic information on the pollinator species associated with each crop and pollinator habitat in which plant provide the nectar, pollen and habitat resources for wild pollinators.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.33-41
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• 2014

In a supersonic turbine, A rotor overlap technique reduced the chance of chocking in the rotor passage, and made the design pressure ratio satisfied. However, the technique also made additional losses, like a pumping loss, expansion loss, etc. Therefore, an approximate optimization technique was appled to find the optimal shape of overlap which maximizes the improvement of the turbine performance. The design variables were shape factors of a rotor overlap. An optimal design for rotor overlap reduces leakage mass flow rate at tip clearance by about 50% and increases about 4% of total-static efficiency compared with the base model. It was found that the most effective design variable is the tip overlap and that the hub overlap size is the lowest.

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.573-580
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• 2013

With the growth of the smart-devices and information & communication technology, information society has developed and information can be produced, spread and consumed at much faster pace easily. Hence, individuals can utilize wireless communication and smart-devices to create, share and consume information at anytime and anywhere. The growth of technology has allowed the large-scale transfer and sharing of image, sound and video data; it changed the users' data consumption pattern that was mainly consisted of the text. Therefore, the amount of data that an individual consumes increased significantly. The importance of finding and analyzing practical and necessary data among huge amount of data has arisen. In this study, the current status of Big Data is researched and analyzed and the method to utilize Big Data in the electronic trading field is suggested.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.167-168
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• 2010

Advanced countries are adopted the Eco-Green port using high energy efficiency Crane and Automated unloading system. This paper includes the case study for energy saving ECO-RTG and other automated unloading system such as, German CTA, Japan OHI, and so on.