• Journal of the Korean GEO-environmental Society
• /
• v.23 no.9
• /
• pp.5-16
• /
• 2022

In recent years due to the development of urban and underground space, the number of ground disasters is increasing, and it is also leading to social problems. To solve the problem, a grouting method is generally used. However, the grouting method has material (grout) limitations in permeability, gelation properties and tensile resistance. Therefore, research on grout materials mixed with fibers is actively carried out to improve the problems. However, in the actual ground injection process, many difficulties have been faced causing the blockage of the inlet port and the injection tube. In this study, 'CNT-mixed grout material' was developed using CNT powder that can reinforce the tensile strength of soils. The uniaxial compressive and tensile strength tests were performed to obtain the optimal content and mechanical properties of the CNT Powder-mixed grout. It was found that the optimal CNT powder content is 0.5% that gives the average maximum strength. A one-dimensional injection test and the bulb formation test were carried out, and it was identified that the injection rate and bulb form could be controlled by pressure and mixing ratio. Field application of the CNT-Mixed grout is simulated using numerical analysis of slopes, foundations, and tunnels reinforced in several types. The positive effect of reducing plastic ranges and settlements was confirmed.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.4 no.1
• /
• pp.80-88
• /
• 2002

This study was carried out to investigate the native distribution and flowering characteristics of Lycoris genus which is endemic species in Asia. This study was summarized as fellows: Native distribution of Lycoris genus was situated in latitude 37- 24 degrees with high humidity of coastline. Mininum temperature of native area was at -10℃ during winter season. The leaf of L. squamigera, L. koreana, L. sangunea, L. sprengeri, L. incanata and L. flavescens emergenced in spring. The leaf of L. radiata, L. rdiata var pumila, L. aurea, L. traubii, L. albiflora and L. houdyshelli emergenced in autum. Bulb of Lycoris genus show a sympodial branching system which is composed of 14-23 scales and 2.8-5.2 leaves per each bulb at flowering time. The flower shape of L. squamigera, L. Koreana, L, aurea, L. incanata, L. sprengeri, L. sanguinea and L. flavescens was trumpet. The flower of L. radiata. L. radiata var pumila, L. albiflora, L. houdchelli and L. traubii. was spider.

• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.407-412
• /
• 1990

This note presents a novel algorithm for a continuous-time direct adaptive pole placement control for single-input single-out nonminimum phase systems. Although the resulting overall closed-loop system is locally stable, assumptions about parameter convergence or the nature of the external input are not considered.

• Proceedings of the KIPE Conference
• /
• 2012.11a
• /
• pp.73-74
• /
• 2012

본 논문은 브릿지형 컨버터에 존재하는 기생성분이 게이트 구동에 미치는 영향을 분석한다. 다양한 기생성분과 입출력 사양에 따라 게이트 구동을 저해하는 EMI의 크기가 어떻게 변하는지 그 관계를 밝힌다. 이론적 분석을 통하여 시뮬레이션 모델을 구축하고, 실험을 통하여 타당성을 증명한다.

• Proceedings of the KIEE Conference
• /
• 1992.07a
• /
• pp.344-346
• /
• 1992

In this paper a robust hybrid control algorithm for n-link nonredundant robot manipulators is proposed. This scheme includes an estimation law for the upper bound on the uncertainty such that robust control input is updated as a function of the estimated upper bound. The uniform ultimate boundedness of the tracking error is generated by the Lyapunov based theory.

• Proceedings of the KIEE Conference
• /
• 1992.07a
• /
• pp.273-275
• /
• 1992

A dynamic system containing uncertain elements is considered. The upper bound of the values of these uncertainties is estimated. Using the estimated value a bounded error state feedback control is proposed based on Corless and Leitmann's result [1].

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1997.05a
• /
• pp.40-45
• /
• 1997

백합 및 아이리스는 국내에서 주로 생산되고 있는 주요 구근식물이다 특히 백합은 95년 일본 및 흥콩으로 232만 달러를 수출하였으며, 앞으로도 수출유망작물로 크게 각광 받을 것이다. 또한 아이리스도 국내 10대 절화작물에 속하는 주요 화훼작물이다. 그러나 국내에서 재배되고 있는 백합 및 아이리스 대부분이 시설내 토양에서 재배되고 있어 합리적인 영양관리가 어려우며, (중략)

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1998.03a
• /
• pp.39-42
• /
• 1998

This paper proposes an adaptive fuzzy control scheme for a class of continuous-time nonlinear dynamic systems for which an explicit linear parameterization of the uncertainty is either unknown or impossible. In order to improve robustness under approximation errors and disturbances the proposed scheme includes deadzone in adaptation laws which varies its size adaptively. The assumption of known bounds on the approximation errors and disturbances is not required since those are estimated using adaptation laws. The overall adaptive scheme is proven to guarantee uniform ultimate boundedness in the Lyapunov sense.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.21-22
• /
• 2012

본 논문은 휴대용 연료전지-배터리 하이브리드 시스템에 적용 가능한 구조들을 비교 분석하고 구조 선정을 위한 가이드라인을 제시한다. 각 구조의 특징 및 장단점을 분석하고 시스템 설계 사양에 적합한 구조를 선정하는 과정을 보인 뒤, 그 타당성을 PSIM 시뮬레이션을 통해 검증한다.

• Journal of Plant Biotechnology
• /
• v.31 no.4
• /
• pp.307-312
• /
• 2004

The bioreactor system for the large-scale plant tissue culture was developed to control the pH concentration and DO (dissolved oxygen), and air flowrate. The system controlling the proper air flow rate for each bulblet growth stage and monitoring the contamination of bioreactor using the pH change was controled by computer program. For the uniform bulblet distribution in bioreactor, the proper air flow rate was 300 cc/min at the beginning of bulblet culture, 400 cc/min after 20 days, 500 cc/min after 40 days, 600 cc/min after 60days, and 700 cc/min after 80 days. It was possible to maintain the pH concentration within 5.5$\pm$0.5 during the culture by control system of bioreactor.