• Journal of Ginseng Research
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• v.26 no.1
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• pp.6-9
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• 2002

This study was undertaken to evaluate the automatic decision-making on the rusty root of fresh ginseng (Panax ginseng C.A. Meyer) by an image analyzer. Critical value of rusty root of ginseng by image analyzing was the percentage of grey value 0∼148 area (G 148) to the total area of grey value 0∼255. And the discriminant formula of rusty root of ginseng as follows; rusty root of ginseng : 6.68$\times$G(148) +3.74, normal ginseng : 2.86$\times$G(148) +9.96, and fitness rates of this formula were 89.8%. Also, we developed the automatic rusty root of decision-making program. As the result of this study, the automatic decision-making on the rusty root of fresh ginseng by an image analyzer seems to have high possibility.

• Convergence Security Journal
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• v.12 no.3
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• pp.107-113
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• 2012

Due to the development of communications technology, it is now possible to be offered online from remote places. This kind of communications technology can be applied to the medical field. The medical treatment appointments in hospitals can be its typical example. But still, in most of hospitals, patient or guardian have to physically visit or call to the hospital to set up an appointment for the medical treatment. In addition, they have to wait in line in order to pay after receiving the medical treatment. The patient or guardian, after paying, receive a paper prescription and they go to a nearby pharmacy to take the medicines. They must wait in line again there in order to receive the medicine from the pharmacy. In this paper, we would like to suggest a smart medical treatment system in order to solve the problems discussed above. With this proposed system, the user will be able to make an appointment, make payments and receive medication quickly and easily without spending extra time. Also, there will be no need for paper prescriptions with this system. We discuss about the security of medical information for this proposed smart medical treatment system proposed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.7
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• pp.1095-1103
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• 1999

Presently, the retractable phone with a whip antenna composed of a helix and a monopole is most widely used for cellular mobile communications. However, since the length of the monopole is usually about λ/4, the strong radiated electric fields are produced in the region where the auricle of a head is contacted directly. This field distribution results in high specific absorption rates(SAR's) in the head. In this paper, SAR distributions and local SAR values for the inversely shaped phone(ISP) whose antenna arrangement is opposite to the original retractable phone(ORP) are compared with those for the ORP. This phone is accomplished by mounting the $\lambda$/4-whip antenna on the bottom, not on the top of the handset. The time-averaged field distribution in a computational space including a human model and a phone model is computed using the finite-difference time-domain(FDTD) method. SAR distributions and local SAR values for these phones are calculated with the field distributions. An anatomical head model and an approximate hand model were used to consider a real situation. From the analyzed data, it is shown that this arrangement of the antenna considerably reduces the spatial peak SAR in a human head.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.6
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• pp.405-413
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• 2019

Deployable structures are widely used for space mission because of their advantages in storage and transportation coming from its transformability of configuration. The space structures should be designed with high stiffness to withstand the various types of disturbance that they encounter during operation. Especially for the deployable structures, the internal forces loaded on the component or the stiffness at its deployed configuration should be analyzed since they usually consist of the thin and light structures. In this paper, a dynamic model of the scissors structure is established and its deployment behavior is analyzed, especially focusing on the deployment speed and the internal force on each joint. In addition, modal analysis is carried out for the 1-stage and 2-stage scissors structures in order to analyze the stiffness of the scissors structure based on its deployed configuration. The fundamental mode shapes and natural frequencies are analyzed and discussed.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.63-72
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• 2022

The purpose of this paper was to understand the dynamics of deployment of large mesh antennas, and to provide a numerical method for determining the dynamic stiffness and the driving forces for the design. The deployment structure was numerically modeled using the frame elements. The eigenvalue analysis was demonstrated, with respect to the folded and unfolded configurations of the antenna. A multibody dynamic model was formulated with Kane's equation, and simulated using the pseudo upper triangular decomposition (PUTD) method for resolving the constrained problem. Based on the multibody model, the kinetics of the deployment, the motor driving forces, and the feasibility of the designed deployment structure were investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.10
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• pp.691-699
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• 2022

Large aperture antennas with long focal lengths in space have important application for telecommunications, Earth observation and science missions. This paper aims to understand the dynamics of deployment of large mesh antennas and to provide a multibody model for determining the driving forces for the design of reflectors and booms. The modular deployable reflector and boom are designed based on the deployment unit cell. A multibody dynamic model is formulated with Kane's equation and simulated using the pseudo upper triangular decomposition (PUTD) method for solving the constrained problem. Based on the multibody dynamic model, the kinetics of the deployment, the motor driving forces, and the structural dynamic deformation are investigated.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.1-9
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• 2023

Recently, as Synthetic Aperture Radar (SAR), communication, and signal surveillance missions of spacecraft have become more advanced, research has been actively conducted on the deployable large mesh antenna system with excellent storage efficiency compared to the deployment area, and light weight. Deployable Mesh antennae are characterized by an increase in the number of Openings Per Inch (OPI), which is a measure of mesh weaving density as the mission frequency band increases, and this OPI change directly affects the thermal optical properties of the mesh antenna, so research on this is required. In this paper, to verify the thermal relationship between the optical properties of the mesh and antenna reflector, thermal sensitivity analysis between the mesh and the antenna reflector is performed by in-orbit thermal analysis with various optical characteristics of the mesh based on existing overseas research cases. In addition, the temperature gradient effect of the mesh reflector is analyzed.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.429-434
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• 2023

Kitchen cabinets are essential furniture for storing the kitchen tools, but their high installed location makes it difficult for users to access the upper of the cabinets. Therefore, in this paper, we propose a new type of kitchen cabinet that allows users to easily take out or store items by adding new height adjustment features while maintaining the function of the existing cabinet. For convenience and safety, an appropriate complex link mechanism is designed so that the selected floor, not the entire cabinet, can come down to a desired height with one operation. Moreover, the optimal descent path is set to prevent the floor tilting or interfloor interference during descent, and appropriate link shapes, lengths, and joint types are selected to implement it. FEA analysis is performed to ensure that the stretched complex linkage can support the load of the stored items and the feasibility of the height adjustable kitchen cabinet is verified through fabrication.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.465-470
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• 2024

Kitchen cabinets are widely used for their spacious storage and efficient use of space, but their high installed location makes it difficult for the elderly and disabled to access. Therefore, in this paper, we propose a new height-adjustable kitchen cabinet that can be used more easily and safely. The lift-down range of cabinet was set considering the installation location of cabinet for efficient use of kitchen space and the maximum height accessible to the elderly and disabled, and the link geometry and driving method of the complex link mechanism were determined through the mechanism design procedure to ensure that the selected floor come down safely along the optimal descend path. In addition, the appropriate motor and control algorithm were added to allow the user to descend to the desired height with a simple button operation. It was confirmed through actual production that the proposed linkage mechanism performs the desired lift-down motion.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.108-116
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• 2009

In this paper, we propose a Ethernet based audio distribution system with a new L1/L2 hybrid switching scheme, and evaluate its performance. The proposed scheme not only offers guaranteed low latency and jitter characteristics that are essentially required for the distribution of high-quality uncompressed audio traffic, and but also provide an efficient transmission of data traffic on the Ethernet environment. The audio distribution system with a proposed scheme consists of a master node and a number of relay nodes, and all nodes are mutually connected as a daisy-chain topology through up and downlinks. The master node generates an audio frame for each cycle of 125us, and the audio frame has 24 time slotted audio channels for carrying stereo 24 channels of 16-bit PCM sampled audio. On receiving the audio frame from its upstream node via the downlink, each intermediate node inserts its audio traffic to the reserved time slot for itself, then relays again to next node through its physical layer(L1) transmission - repeating. After reaching the end node, the audio frame is loopbacked through the uplink. On repeating through the uplink, each node makes a copy of audio slot that node has to receive, then play the audio. When the audio transmission is completed, each node works as a normal L2 switch, thus data frames are switched during the remaining period. For supporting this L1/L2 hybrid switching capability, we insert a glue logic for parsing and multiplexing audio and data frames at MII(Media Independent Interlace) between the physical and data link layers. The proposed scheme can provide a good delay performance and transmission efficiency than legacy Ethernet based audio distribution systems. For verifying the feasibility of the proposed L1/L2 hybrid switching scheme, we use OMNeT++ as a simulation tool with various parameters. From the simulation results, one can find that the proposed scheme can provides outstanding characteristics in terms of both jitter characteristic for audio traffic and transmission efficiency of data traffics.