• The Korean Journal of Food And Nutrition
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• v.34 no.2
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• pp.217-223
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• 2021

Vegetable oils are a rich source of bioactive substances. Phytosterols in those have been known for many years for their properties for reducing blood cholesterol levels, as well as their other beneficial health effects. Phytosterols are triterpenes that are important structural components of plant cell membranes just as cholesterol does in animal cell membranes. The aim of this study was to provide consumers with information about phytosterol contents in vegetable oils in Korea market. The contents of major phytosterols (campesterol, stigmasterol, β-sitosterol) in 50 vegetable oils of 10 kinds (perilla oil, peanut oil, avocado oil, olive oil, pine nut oil, sesame oil, canola oil, coconut oil, grape seed oil, and sunflower oil) were analyzed by gas chromatography with flame ionization detector. The average contents of vegetable oils containing 5 or more samples were in the order of sesame oil (334.43 mg/100 g), perilla oil (262.16 mg/100 g), grape seed oil (183.71 mg/100 g), and olive oil (68.68 mg/100 g). Phytosterol content of sesame oil and perilla oil was high among vegetable oils.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.401-407
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• 2016

This paper introduces 3-dimensional path planning and guidance including power model for high altitude long endurance (HALE) UAV using solar energy. Dubins curve used in this paper has advantage of being directly available to apply path planning. However, most of the path planning problems using Dubins curve are defined in a two-dimensional plan. So, we used 3-dimensional Dubins path generation algorithm which was studied by Randal W. Beard. The aircraft model which used in this paper does not have an aileron. So we designed lateral controller by using a rudder. And then, we were conducted path tracking simulations by using a nonlinear path tracking algorithm. We generate examples according to altitude conditions. From the path tracking simulation results, we confirm that the path tracking is well on the flight path. Finally, we were modeling the power system of HALE UAVs and conducting path tracking simulation during 48hours. Modeling the amount of power generated by the solar cell through the calculation of the solar energy yield. And, we show the 48hours path tracking simulation results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.2
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• pp.147-154
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• 2024

This study focuses on the path planning algorithm for large-scale autonomous delivery using drones and robots in urban environments. When generating delivery routes in urban environments, it is essential that avoid obstacles such as buildings, parking lots, or any other obstacles that could cause property damage. A commonly used method for obstacle avoidance is the grid-based A* algorithm. However, in large-scale urban environments, it is not feasible to set the resolution of the grid too high. If the grid cells are not sufficiently small during path planning, inefficient paths might be generated when avoiding obstacles, and smaller obstacles might be overlooked. To solve these issues, this study proposes a method that initially creates a low-resolution wide-area grid and then progressively reduces the grid cell size in areas containing registered obstacles to maintain real-time efficiency in generating paths. To implement this, obstacles in the operational area must first be registered on the map. When obstacle information is updated, the cells containing obstacles are processed as a primary subdivision, and cells closer to the obstacles are processed as a secondary subdivision. This approach is validated in a simulation environment and compared with the previous research according to the computing time and the path distance.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.667-669
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• 2006

• ETRI Journal
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• v.25 no.6
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• pp.523-526
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• 2003

This letter presents an approximation of the outage probability of the pilot channel that can be used for CDMA cell planning. The approximation can determine system parameters for soft handover in IS-95-based cellular CDMA downlink design. Computer simulations show that our analytical results agree with empirical results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.17-17
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• 2004

자율 이동로봇은 현재 각광을 받고 있는 서비스로봇의 연구와 더불어 활발히 연구되고 있다. 그 중 경로계획 부분에 대한 연구는 Roadmap Method, Cell Decomposition, Potential Field Method로 크게 구분하여 연구되고 있다. 그러나 경로계획 기법에 있어서 기존의 정형화된 방법 이외에 다른 방법들이 제시 되지 않고 있다. 기존 경로계측의 문제점들은 다음과 같다. 국부최소(local minimum)를 회피하지 못하거나, 많은 계산량으로 인해 넓은 범위에 적용시킬 수 없다는 문제점, 오프라인으로 경로의 최적성에만 치중하여 실시간으로 적용하기가 쉽지 않으며, 돌발적인 상황에 대처하기 어렵다는 문제점 등을 가지고 있다.(중략)

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.46-49
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• 2007

Multiple Antenna Technologies such as Multiple-Input Multiple-Output (MIMO) and Beamforming provide the increase of channel capacity and the reliability of wireless link. To obtain these advantages, WiBro, Mobile WiMAX and $4^{th}$ Generation System are employing multiple antenna technologies. There exist, however, many technical issues in considering the application of the technologies or the providing of services using them. In this paper, various technical topics are discussed and simple solutions are proposed. Beamforming has several technical issues which include coverage imbalance, difficulties in providing Multicast-Broadcast Service (MBS). In Addition, network planning is a critical point from a cell extension and initial network entry point of view. In case of MIMO, network deployment is discussed in that cellular data network such as WiBro has many repeaters. MIMO mode selection for maximizing the cell capacity is also covered.

• Journal of Astronomy and Space Sciences
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• v.15 no.2
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• pp.341-358
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• 1998

The X-ray astronomy team of the Korea Astronomy Observatory(KAO) is planning to develop a multi-cell proportional counter, adopting an anti-coincidence method to reduce its internal background. We have developed a Monte Carlo code to determine the X-ray detection efficiency of the counter. As a check of our code, we successfully reproduced the detection efficiency of Ginga/LAC. In this paper, we report the simulation results for the counter being considered in KAO.

• Computers and Concrete
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• v.5 no.6
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• pp.545-558
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• 2008

The corrosion of RC structures demonstrates very complicated forms of deterioration intermingled together but all pointing to a decrease in the durability of RC structures due to the corrosion of reinforcing bars. Until now, nondestructive techniques, such as half-cell potential and polarization resistance, have been widely available in the world. The former provides information on the probability of corrosion while the latter is associated with information concerning corrosion rates. Inversion by the boundary element method (IBEM) was developed for considering concrete resistivity. The applicability of the procedure was examined through a numerical analysis and electrolytic tests for RC slabs. A distribution in such concrete resistivity is relatively inhomogeneous including cracks on the surface of slabs. Regarding cracks in concrete, the relative coefficient of concrete resistance was introduced to perform its analysis. Further, the procedure will be developed to identify the corroded region visually using 3-D VRML.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.203-207
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• 2009

WiBro(Mobile WiMAX) has gained momentum as a top candidate to deliver the dream of full mobile wireless internet. To save cost and time in WiBro network design, simulation tool has to deploy powerful and useful analysis functions. If path loss model is more accurate, the reliability of analysis result of simulation tool will be much improved. So we emphasize on the importance of pathloss model in WiBro network design in this paper. For this, we introduce to three kinds of pathloss models(SUI, SCM, SCM-E) supposed properly models in WiBro RF (Radio Frequency) environment. Also we treat from basic theory to practical substance on the pathloss model to adopt WiBro network design/optimization. Finally, we describe about wireless network analysis tool named 'CellPLAN(R)' and techniques possible to improvethe accuracy of pathloss model.