• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.440-445
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• 2003

식물의 공장적 생산에 있어서 재배적인 측면에서 중요한 요소 중의 하나는 환경조절과 양액제어 그리고 종자발아기술, 녹화기술일 것이다. 그 중에서도 종자를 파종한 후의 발아기간이 일정하지 않거나 조절이 어려우면 엽채류의 공장적 생산에서 중요한 매일 정식, 매일 수확이 어렵게 된다. 일반적으로 상추의 발아적온은 18-$25^{\circ}C$이다. 그러나 작물생육에 중점을 두어 환경을 조절하는 현재의 제어온실내에서는 발아적온을 맞추기가 어렵다. 따라서 별도의 발아장치가 필요하다. (중략)

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.299-304
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• 1991

A novel approach based on a nonlinear compensator is proposed to prevent 'windup', which is caused by the saturation of the actuator and the integration action of the controller. The anti-windup compensator is located between the conventional linear controller, designed neglecting the saturation, and the actuator. It was proven based on the describing function method that, if the closed loop control systems are stable assuming no saturation, then there exist a range of compensator gain which prevents any limit-cycle and hence, guarantees the system stability. The computer simulation results show that the compensator proposed in the manuscript can eliminate unstable limit cycle and improve the transient response.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.23-23
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• 1999

일반적인 제어대상 시스템을 모델링하여 제어기를 설계할 경우 시스템을 제어하는 액츄에이터의 saturation 현상을 무시하고 설계하는 경우가 자주 있다. 만일 시스템이 SISO이며, 충분히 안정하고 동적 특성이 빠른 경우에는 saturation 무시가 주는 영향이 크게 나타나지 않지만, 만일 시스템이 MIMO이며 비선형일 경우 비선형 요소인 입력 saturation에 의하여 시스템의 특성이 변형되고 크게는 불안정화 된다.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.369-370
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• 2019

"색채"는 디지털 미디어 제작에서 가장 중요한 요소 중 하나이다. 디지털 시대에서 색채의 활용과 처리는 영화의 예술 표현에 직접적인 영향을 미치고, 초기 촬영 소재의 대비도, 밝기, 색채 포화도 면에서의 부족함을 보완하기 위해 또는 색채로 영화의 분위기를 나타내기 위해 영화 후반작업 과정에서 영화에 대해 색채 보정을 진행해야 한다. 본문은 영화에서 색채의 예술적 표현을 분석하고 디지털 색채 보정의 기본 방법을 설명하여, 색채 보정은 디지털 미디어 제작에서 없어서는 안될 작업 프로세스임을 입증하고자 한다.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.73-84
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• 2001

Korean Highway Capacity Manual applies 7 adjustment factors to estimate saturation flows at signalized intersections. Among the adjustment factors, the right-turn adjustment factor uses equation hard to understand and requires complicated computing process comparing other adjustment factors. Thus. this study was conducted in order to suggest a new technique of estimating the right-turn adjustment factor which is easy to understand and simple to computer by having reasonable degree of accuracy. In this study the right-turn saturation flow ratios which are important in estimating the factor are suggested and the equation to estimate the volume of right-turn on red signal(RTOR) is developed based on observed data. The right-turn saturation flow rates can be estimated according to turning radius and number of lanes of crossing road dividing right-turn lanes into canalized and uncanalized lanes. The RTOR volume is estimated using the proportion of the time during which RTOR is possible to the whole time of red signal according to the through traffic volume per lane of the approach at signalized intersections. The technique of estimating the right-turn adjustment factor suggested in this study, which follows the HCM2000 of U.S. in principal, first judges the right-turn lane to be used exclusively for right-turn or not by employing the RTOR factor and the judging equation developed in this study. Next, if the right-turn lane is not exclusive right-turn lane, the shared right-turn lane is classified into single lane approach or multi lane approach. Thus, a total of three methods of estimating the right-turn adjustment factor to the three cases are suggested in this study.

• Journal of the Korean Geotechnical Society
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• v.35 no.11
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• pp.7-14
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• 2019

The compacted bentonite buffer is one of the major components of an engineered barrier system (EBS) for the disposal of high-level radioactive waste (HLW), and it is considered the best candidate for the buffer material. The buffer is located between disposal canisters and near-field rock mass, and it interrupts the release of radionuclide from disposal canisters and protect them from the penetration of groundwater. At initial disposal condition, degree of saturation of the compacted bentonite buffer decreases because of high thermal quantities released from the disposal canisters. However, the degree of saturation of the compacted bentonite buffer gradually increases caused by inflow of groundwater. The saturated and unsaturated behavior of the buffer is a very important input data since it can determine the safety performance of EBS. Therefore, this paper investigated water retention capacity (WRC) for the Korean compacted bentonite buffer. The WRC of the compacted bentonite buffer was derived by measuring volumetric water content and water suction when temperature variation was between 24℃~125℃ considering decrease of degree of saturation with respect to temperature increase. The WRC was also derived with the same volumetric water content under the room temperature condition, and it showed 1~15% larger water suction than high temperature condition.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.218-226
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• 2014

This study examines a way to install a crosswalk that can improve pedestrians' convenience and safety and that goes beyond the crosswalk design standard of existing roundabouts. When a scrambled crosswalk, one of the crosswalk installation methods, is introduced to the roundabout system, it shortens the cross-walking distance of pedestrians and thus enhances convenience. Although the installation of a scrambled crosswalk may enhance pedestrians' convenience, it may obstruct vehicular traffic. Thus, this study presents standards for reasonable diagonal crosswalk installation based on the investigation on its effects on a vehicle's delay time. This study includes an analysis of the various geometric structures of roundabouts. The study results show that as v/c and the number of pedestrians increased, the delay time after the installation of a scrambled crosswalk increased although the extent was different. In general, the effect of the installation of a scrambled crosswalk was insignificant regardless of the number of pedestrians when v/c was under 0.6. When the number of pedestrians was 300/hour or lower, the difference in the delay time was quite insignificant regardless of v/c. In addition, as the inscribed circle of the roundabout was larger, the difference in the delay time decreased depending on v/c and the number of pedestrians.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.55-68
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• 2008

At present underground structures such as road tunnels, railway tunnels, underground petroleum storages and radioactive waste storages are being constructed in numerous places in Korea. For the construction of underground structrues, it should be accounted for natural factors (geology, hydrogeology, soil, vegetation, topography and drainage patterns) and human-social factors (land use, urbanization, population, culture and transportation). Especially, hydrogeology should be regarded as an important factor for evaluating the safety of underground structures and their impact to groundwater system around the structures. This study aimed to recognize hydrogeological characteristics of shallow formations in the area from Dongrae crossway to Seo-Dong where 45 boreholes were drilled for the construction of Line-3 subway in Busan Megacity. Slug tests for unsaturated and saturated zones were conducted on 30 boreholes in the study area. From the result of the slug tests, it was identified that average zonal hydraulic conductivity in the unsaturated zone was higher than that in the saturated zone. Besides, the slug test result in the saturated zones may reflect hydraulic properties of the upper most part of the saturated zones.

• Journal of the Korean GEO-environmental Society
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• v.10 no.3
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• pp.13-20
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• 2009

Generally, soil is regarded as fully saturated in Geotechnical Engineering and under ground structure design. Because it is in convenience and safety. But soils treated in field are almost in unsaturated state. Design in unsaturated state is difficult comparing with saturated soil. In unsaturated soil mechanics, parameters are usually not constant unlike saturated soil mechanics. Additionally lab or field tests in unsaturated soil mechanics are required more cost, time and theoretical difficulty. One of essential requisites for examination about unsaturated soil is Soil-Water Characteristic Curve (SWCC). It show the relation between soil suction and soil water content. Through many studies in and out of country, computation and testing methods for SWCC were introduced. But in this the country, most soil is granite soil that is widely spread in Korea. And the studies for granite soil's SWCC are not enough yet. In this paper, through studying for existing proposal methods about computation SWCC and collection data for domestic granite soils, It was determined the suitable method for domestic granite soils, and computed each granite soil's SWCC. The purpose of this paper is establishing database for domestic granite soil's SWCC as each region to convenience for applying to actual affairs. For this, studying about existing proposal methods for SWCC was performed and a computer program Soil-Vision is used. Furthermore for verification theoretical and testing methods were also performed.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.2 s.13
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• pp.19-27
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• 2004

The interest in the dynamic properties of soils has increased strongly because of earthquake, heavy traffic, and foundations undergo high amplitude of vibrations. Most of soils in Korean peninsula are composed of granite soils, especially the decomposed mudstone soils are widely spread in Pohang areas, Kyong-buk province. Therefore, it is very important to investigate the dynamic properties of these types of soils. The most important soil parameters under dynamic loadings are shear modulus and material dampings. Furthermore, few definitive data exist that can evaluate the behavior of unsaturated decomposed mudstone soils under dynamic loading conditions. The investigations described in this paper is designed to identify the shear modulus and damping ratio due to a surface tension for the unsaturated decomposed mudstone soils under low and high strain amplitude. For this purpose, the resonant column test and the cyclic triaxial test were performed. Test results and data have shown that the optimum saturated degree of decomposed mudstone soils under low and strain amplitude is $32{\sim}37%$ which is higher than that of decomposed granite due to the amount of fine particles as well as the type and proportion of chief rock-forming minerals.