• Tunnel and Underground Space
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• v.23 no.1
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• pp.54-65
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• 2013

The LCM (Linear Cutting Machine) test is one of the most powerful and reliable methods for designing the disc cutter and for predicting the TBM (Tunnel Boring Machine) performance. It has an advantage to predict the actual load on disc cutter from the laboratory test on the real-size large rock samples, however, it also has a disadvantage to transport and/or prepare the large rock samples and to need an extra cost for experiment. In order to overcome this problem, lots of numerical studies have been performed. In this study, the PFC3D (Particle Flow Code in 3 Dimension) has been adopted for numerical analysis on optimum cutter spacing and failure aspects of Busan Tuff. The optimum cutting condition with s/p ratio of 16 and minimum specific energy of $14MJ/m^3$ was derived from numerical analyses. The cutter spacing for Busan Tuff had the good agreements with those of LCM test and numerical analysis by finite element method.

• Journal of Biosystems Engineering
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• v.13 no.2
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• pp.18-27
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• 1988

The basic model of impeller was developed for the theoretical analysis of performance. The developed model was tested with two different blade radius of curvature based on the pumping efficiency under the operating conditions in Korea. And the pump performance of the impeller was also tested for the various speeds. The results obtained are summarized as follows; 1. There was no significant effect on the different blade radius of curvatures on the discharge and pump efficiency. 2. Head and power requirement was increased in proportion to the blade radius of curvature. 3. In the mathematical approach of the blade radius of curvature, the method of involute curve was more recommendable as compared with the method of circular arc curve. 4. The pump efficiency of the model impeller developed based on the theoretical analysis increased about 10% more than that of the existing impeller.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.1
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• pp.72-86
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• 2006

A technical review of current ramjet propulsion is presented. In addition to summarize the current status of ramjet technology, new key techniques like Boosting technique easily adapting total impulse of booster, flame stabilization technique with minimized ramjet combuster length, variable nozzle-inner-surface technique realizing wide flight-envelop, and thermal protection technique for long operating time are identified. Actually various Ramjet propulsion technology has been matured and expanding to both military and combined cycle application. Yet many opportunities remain to be challenged by future generations of explorers to utilize s typical ramjet propulsion system for multi-purpose(multi-platform and multi-target) missiles, for example, American JSSCM and Russian Yakhont missiles, improving both reliability of techniques and downsizing development cost of new propulsion system.

• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.156-165
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• 1983

This experiment was carried out to elucidate the drying characteristics of onion and dehumidifying effect of air using the silica gel and to reuse it by solar collector. The results were summarized as follows. 1. It takes 14hours to regenerate to silica gel of 8% moisture content from saturated silica gel in conditions of $28^{\circ}c$ temperature and 55% relative humidity. 2. When sample was recycled through solar collector, the result of drying was 1/2 times more efficient than that of mat drying. 3. Average thermal efficiency of solar collector was 25% during the experimental period. 4. Browning extent was reduced to 1/2 times at heated air blow drying system using drying chamber.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.171-178
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• 2006

The seismological observation of Korea began in 1905, and has been run with continuous earthquake network of observation, expanding to the advanced country, but still has some problems in accuracy and speed for report. There are many problems to announce the early warning system for earthquakes and tsunami in the East Sea because most events in the East Sea occur outside the seismic network. Therefore multi-waveform data conversion and composition from the surrounding countries such as Korea, Japan and Far East Russia are requested in order to improve more accurate determination of the earthquake parameters. We used FESNET(Far East Seismic Network) technology to analyze the May 29 and June 1 Earthquakes, and the March 20, 2005 Fukuoka Earthquake in this research, using the data sets of KMA, Japan(JMA/MIED) and IRIS stations. It was found out that use of FESNET resulted in more better outputs than that of a single network, either KMA or JMA stations.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.703-706
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• 2010

A new gerbera cultivar 'Sunny Lemon' was released by the National Institute of Horticultural and Herbal Science (NIHHS) in 2009. A cross was made between 'Pavlov' and 'Patrick' with pink and semi-double in 2006. After investigation of the characteristics for four years (from 2006 to 2009), it was selected for the use of cut flower. 'Sunny Lemon' is a vigorous cultivar with yellow flower color (RHS Y9C), brown center and semi-double. The average flower diameter is 11.0 cm. And inner ray floret and disc diameter are 7.63 cm and 2.59 cm, respectively. Days to first blooming are 84.5, approximately 2 weeks earlier than the standard cultivar. It produces a large yield with continuous supply of cut flowers and has adequate peduncle height. We believe that 'Sunny Lemon' has a great potential for expanding cultivated area of domestic gerbera cultivars and increasing farmers' income.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.79-79
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• 2019

홍띠(Imperata cylindrica 'Rubra') 식물자원의 기내대량증식과 재분화식물체의 순화체계를 구축하고자 기내 재분화에 적합한 식물재료부위, 생장조절물질을 조사하고, 재분화 유식물체로부터 적정 순화조건을 구명하였다. 기본배지로 MS (Murashige and Skoog, 1962) 배지를 사용하였고, 배양은 $26{\times}2^{\circ}C$, $25{\mu}mol/m^2/s$, 14h/10h (day/night) 광조건 하의 배양실에서 수행하였다. 캘러스 형성은 뿌리 끝, 줄기절편, 생장점 부위 중생장점 부위에서 가장 양호하였고, 이 생장점 조직에 0.1 mg/L의 2,4-D와 2 mg/L의 BA를 처리하였을 때 양호하였다. 캘러스 증식은 0.1 mg/L의 2,4-D와 0.05 mg/L의 BA 배지, 0.05 mg/L의 2,4-D와 0.5 mg/L의 BA를 첨가한 배지 중 0.1 mg/L의 2,4-D와 0.05 mg/L의 BA 배지에서 양호하였고, 이들 캘러스로부터 신초 재분화는 0.01 mg/L의 NAA와 2 mg/L의 BA 처리에서 양호하였다. 초기 치상으로부터 실제 경과시간은 캘러스 유도에 19주간(2018. 03. 18~07. 27), 캘러스 증식 9주간(2018. 07. 27~09. 28), 신초 유도 11주간(2018. 09.28~12. 14), 순화에 10주간(2018. 12. 14~2019. 02. 23)에 걸쳐 진행하였으나 확립된 배양계를 적용하면 캘러스 유도 4주, 캘러스 증식 3주, 신초유도 및 증식 ４주, 순화 ７주 정도가 소요될 것으로 계측되었다. 순화는 다경줄기 형성후 MS배지를 멸균한 상토(버미큘라이트) 또는 종이포트로 교체하여 재분화식물체를 배양병에서 7주간 배양하고, 7주후에 배양병 뚜껑을 1/10 정도 1차 개방하여 1주일 후 3/10 정도 개방하여 2주간 경과한 후 컵포트(직경 6 cm)에 이식하여 성공적으로 활착시켰다.

• Convergence Security Journal
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• v.21 no.2
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• pp.67-79
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• 2021

Lessons Learned(LL) is a military term defined as all activities that promote future development by finding problems and need improvement in education and reality in the field of warfare development. In this paper, we focus on presenting actual examples and applying AI analysis inference techniques to solve revealed problems in promoting LL activities, such as long-term analysis, budget problems, and necessary expertise. AI legal advice services using cognitive computing-related technologies that have already been practical and in use, were judged to be the best examples to solve the problems of LL. This paper presents intelligent LL inference techniques, which utilize AI. To this end, we want to explore theoretical backgrounds such as LL analysis definitions and examples, evolution of AI into Machine Learning, cognitive computing, and apply it to new technologies in the defense sector using the newly proposed L²-OODA ensemble algorithm to contribute to implementing existing power improvement and optimization.

• Journal of Industrial Convergence
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• v.18 no.6
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• pp.27-32
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• 2020

Recently, as the business using IT has increased rapidly, a lot of budget is required to operate and manage the complex IT infrastructure. There is a need for a new IT infrastructure technology that can effectively and reduce costs. In this paper, we introduce CI(Converge Infrastructure) and HCI(Hyper Converge Infrastructure) methods, which are IT infrastructure methods for simplifying information systems and reducing operational management efficiency and cost. In addition, it proposes an information system using the HCI method, a new IT infrastructure technology, and a plan to establish a disaster recovery system to provide continuity of service in the event of a disaster or failure. In addition to the introduction of major technologies for using the HCI method, the area, power consumption, and operational efficiency of the information system before and after the introduction of HCI are compared and analyzed.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.1
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• pp.65-70
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• 2023

The effect of improvement by keeping the former as the priority was examined through an evaluation of the role of the blood transfusion management (BTM) division. This division manages the status of blood for transfusion, evaluates the adequacy of blood transfusion (EABT), monitors and responds to the occurrence of transfusion-related side effects, and performs other tasks necessary for BTM. Although the establishment and operation of the BTM division can lead to the efficient evaluation of transfusion adequacy, there are disadvantages in that it takes time for EABT and it is difficult for the staff in charge of the BTM division to evaluate the adequacy of all the blood. In the future, it is essential to introduce a BTM division and committee specific to Korean patients to implement safe and appropriate BTM in medical institutions, and to assist medical institutions in training their personnel.