• Applied Biological Chemistry
• /
• v.21 no.1
• /
• pp.58-62
• /
• 1978

Dry weight, and mineral content in leaves, stems, and roots of the ginseng plant (Panax ginseng C.A. Meyer) were investigated. The highest T/R ratio, 0.52, was observed in a four year old plant due to a vigorous growth of the plant at this age. Also the dry weight increase was rather higher in the younger root than the older one. Mineral content of the plant was rather higher in the younger root than the older one. Potassium content in leaves and stems was higher than those of nitrogen and phosphorus. Generally, the leaves contained more iron and manganese than any other micronutrients. The iron content amounted to $1,000{\sim}2,000ppm$ in leaves. Zinc content was higher in stems and leaves than roots especially in stems of the younger roots. Total amount of the up-taken N, $P_2O_5$, and $K_2O$ per 10a in six years was 10.2kg, 2.3kg and 14.9kg respectively, indicating the considerable abounts of $K_2O$ was absorbed.

• Journal of Korean Society of Forest Science
• /
• v.21 no.1
• /
• pp.35-38
• /
• 1974

In order to investigate reproductive capacity of genus Lespedeza 5 spp,; L. bicolor, L. maximowiczii, L. japonica var. intermedia, L. angustifolioides, and L, cyrtobotrya, their hights, diameter at the ground level, and the number of sprouts were compared with each other at the end of October during investigating years from 1970 to 1972. For measuring of invested items, 6 stocks which the one-year aged stem were cut above ground were randomly planted per square meter with six replications at the spring of 1970. After hights, diameter, and the number of sprouts were measured at the end of October every year, the stem were cut above ground at the end of November from 1970 to 1972. The results are as follows: 1. The reproductive of the stems showed statistically significant differences at 1% level by species and stock ages. L. bicolor showed the best reproductive capacity of them. 2. The sprouting ability was revealed that L. maximowiczii showed the best of them. 3. The reproductive capacity of stem, diameter, and number of sprouts increased with aging of stock up to 4 years on the investigated 5 species.

• Applied Biological Chemistry
• /
• v.30 no.4
• /
• pp.340-344
• /
• 1987

Saponins of ginseng root, leaf and stem were identified by TLC. Eleven unknown spots were detected in ginseng leaf and ten unknown spots in ginseng stem on TLC besides seven ginsenosides such as $ginsenoside-Rg_1,\;-Rf,\;-Re,\;-Rd,\;-Rc,\;-Rb_2,\;and\;-Rb_1$ which are contained in ginseng root. $Ginsenoside-Rg_3\;and\;-Rg_2$ were identified on TLC from mild hydrolysates with 50% acetic acid of total saponins from ginseng root, leaf and stem. Meanwhile, panaxadiol, panaxatriol and oleanolic acid were identified from hydrolysates with 7% ethanolic sulfuric acid of total saponin of ginseng root, while panaxadiol and panaxatriol from those of total saponins of ginseng leaf and stem.

• Journal of the Korean Society for Railway
• /
• v.10 no.5
• /
• pp.589-595
• /
• 2007

Korea Railroad Research Institute has developed the driverless rubber-tired K-AGT (Korean-Automated Guideway Transit) system from 1999 to 2005 and has done its performance and reliability tests on the test line at Gyeongsan-city. Radio Frequency Communication-Based Train Control system of K-AGT, which employed Advanced Automated Train Control scheme, detects train position using the radio propagation delay between wayside and vehicle radio equipment. In this paper, we investigate whether the transmission power of radio system can be reduced to the permitted level announced by the Ministry of Information and Communication for license-free ISM(Industrial Scientific Medical) frequency bands. We first determine radio propagation model, using the measured data at test line, and perform simulation for radio coverage prediction. From the simulation results, we identify that the radio system operated with reduced power can provide good link quality in total test line.

• Journal of Aerospace System Engineering
• /
• v.13 no.3
• /
• pp.15-22
• /
• 2019

In this paper, a global and local flight path system for autonomous flight of the UAV is proposed. The overall system is based on the ROS robot operating system. The UAV in-built computer detects obstacles through 2-D Lidar and generates real-time local path and global path based on VFH and Modified $RRT^*$-Smart, respectively. Additionally, a movement command is issued based on the generated path on the UAV flight controller. The ground station computer receives the obstacle information and generates a 2-D SLAM map, transmits the destination point to the embedded computer, and manages the state of the UAV. The autonomous UAV flight system of the is verified through a simulator and actual flight.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.19 no.4
• /
• pp.37-43
• /
• 2011

Lunar exploration program has been prepared with the aim of launch in the 2020's. As part of it, a lunar lander demonstrator has been developed which is the model for verifying all the system, such as structure, propulsion and control system before launch to deep space. After verifying all the system, the demonstrator will be evaluated by flight test. This paper deals with path tracking controller based on thrusters for the demonstrator. For this, first we derive equations of motion according to the allocation of thrusters and design the path tracking controller. The signal generated from the controller is continuous so PWPF(Pulse-Width Pulse-Frequency) modulator is adopted for generating on/off signal. Finally MATLAB simulation is performed for evaluating the path tracking ability and the final landing velocity.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.11
• /
• pp.1042-1051
• /
• 2011

In this paper, a total operating environment equipped with onboard wireless communication systems and ground-based mission control systems is proposed for simultaneous operation of multiple UAVs. A variety of operating structures are studied and classified systematically based on types and usages of the components. For each operating system, the strength, weakness and reliability aspects are investigated. Based on these results, a proper operating system configuration is determined and components are developed for mission formation flight. Proposed system can make a formation flight of various UAVs, execute complex missions decentralizing mission to several UAVs and cooperate several missions.

• Journal of Korea Foresty Energy
• /
• v.21 no.3
• /
• pp.28-33
• /
• 2002

This study was carried out to develop the technique for the production of high quality container seedlings of Comus controversa Hemsley. The seedlings were grown on the medium of peatmoss : perlite : vermiculite (1:1:1, v/v) in plastic net container and no-net plastic container as control for five months in the PE house. The seedlings grown in the plastic net container showed better root collar diameter growth, better development of long and fine roots, more increment of dry mass of roots and shoots than those grown in the no-net container. But the height growth of the seedlings in both container was similar. In particular the seedlings grown in plastic net container had no spiraling roots which were always observed in the control container seedlings. This result was induced by air-root pruning effect from the plastic net container.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.144-147
• /
• 2017

A hybrid rocket engine capable of thrust throttling and underwater-working was developed for the underwater high-speed vehicle propulsion system. The hybrid rocket engine was designed and made by two types of ground test motor and underwater working motors. An engine performance was verified by the ground tests with the ground test motor and in the case of underwater motors the ground tests and underwater tests were performed. For the underwater operation a two-stage ignition system was adopted and a rupture disc was installed at the end of nozzle for a water-tight just before an ignition. Successful ignition and propulsion were confirmed in the underwater test with the final selected double rupture disc.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.2
• /
• pp.187-192
• /
• 2009

Telecommand & telemetry control equipment is needed for the testing of the transponders during the development of satellite. This equipment must have a loopback function to perform the self testing without satellite. The fabrication of the designed system is easier and cheaper than the conventional testing system using direct modulation method. The measured results of fabricated equipment are satisfied with required specifications. A overall path loss of uplink and downlink is 47.8 dB and 42.6 dB, respectively. Also, IMD3 of uplink has measured 60.68 dBc at an output of -50 dBm.